Astronomical dating of Roman time

Abstract

Published or otherwise available European oak tree-ring chronologies archaeologically anchored in Roman time are all separated from early medieval chronologies by a severe timber depletion in late antiquity. Our recent dendrochronological study shows that this gap probably is unnecessarily wide because the Roman dendro complex as a whole appears dated too old by 218 years.

The subject of the here presented astronomical study was to investigate if there is additional scientific support for such a mistake which would mean a large calendar error in the Christian era. Our results indicate that the Christian era was inflated with 232 years already when it was invented. This was done by backdating West-Roman and related history by means of astronomical retrocalculation after the western part of the Roman empire had declined.

A remarkable result of our astronomical study is that the postulated astronomical/ historical error (232 years) appears to be offset by 14 years from the dendrochronological error (218 years). This means that, if we are right, then all current dendrochronological dates within the Roman time complex are given 14 years too young. According to our interpretation, the 14 years offset was caused by an improper synchronization of the Roman dendro complex towards Roman history done more than 30 years ago.

Full text

Astronomical dating of Roman time, draft, 2016-02-27, Page 1 of 49
Astronomical dating of Roman time
Petra Ossowski Larsson* and Lars-Åke Larsson, Sweden
* Corresponding author: petra@cybis.se
Abstract
Published or otherwise available European oak tree-ring chronologies
archaeologically anchored in Roman time are all separated from early medieval
chronologies by a severe timber depletion in late antiquity. Our recent
dendrochronological study shows that this gap probably is unnecessarily wide
because the Roman dendro complex as a whole appears dated too old by 218 years.
The subject of the here presented astronomical study was to investigate if there is
additional scientific support for such a mistake which would mean a large calendar
error in the Christian era. Our results indicate that the Christian era was inflated with
232 years already when it was invented. This was done by back-dating West-Roman
and related history by means of astronomical retrocalculation after the western part
of the Roman empire had declined.
A remarkable result of our astronomical study is that the postulated astronomical/
historical error (232 years) appears to be offset by 14 years from the
dendrochronological error (218 years). This means that, if we are right, then all
current dendrochronological dates within the Roman time complex are given 14
years too young. According to our interpretation, the 14 years offset was caused by
an improper synchronization of the Roman dendro complex towards Roman history
done more than 30 years ago.
What is the problem?
In the early 1990:s, the people around Heribert Illig and Hans-Ulrich Niemitz (ref.1)
formulated the following hypothesis:
Between Antiquity (1 AD) and the Renaissance (1500 AD) historians count
approximately 300 years too many in their chronology. In other words: the
Roman emperor Augustus really lived 1700 years ago instead of the
conventionally assumed 2000 years.
The group based this hypothesis on lots of indications from written and
archaeological sources and architectural considerations, and postulated that the time
between 614 and 911 was invented for various reasons later in the Middle Ages. In
our opinion, a more robust indication for the existence of a phantom time might be
their observation that the Gregorian calendar reform possibly does not account for all
the years said to have elapsed since the introduction of the Julian calendar.
We heard about this hypothesis in connection with the turn of the millennium,
because if the above statement would be true also the starting point of our time count
(the birth of Jesus Christ which according to the New Testament took place during
Roman emperor Augustus' reign) would have been c. 300 years later. This means

Astronomical dating of Roman time, draft, 2016-02-27, Page 2 of 49
either that Jesus was born around year 300, or we had nothing to celebrate because
the actual year count would be c. 1700 instead of 2000.
With effective tools right at our hands, we thought that dendrochronology would be a
suitable method to show if there were invented years in our historical calendar, thus
rejecting or confirming the very basis for this hypothesis. Therefore we started a
project to show with dendrochronology where tree-ring sequences measured from
wood with archaeologically Roman origin fit on the existing long European tree ring
chronologies (ref.2).
The first result was that there is a weak period of about two hundred years in virtually
all published European oak chronologies between Roman time and early medieval
time. This weak period, called the "Roman gap", is also apparent in tree ring
chronologies of various wood used for building in the Aegean (ref.3). Moreover,
because of difficulties to reliably bridge this gap it had been necessary to "calibrate"
the Roman complex of the Middle European oak chronology with historical
considerations (ref.4 and Appendix E).
This result was not expected and definitely not suitable for rejection of the hypothesis
about invented years in our history. We gave the case a second try and found a
significant correlation between a long continuous north-west European oak
chronology anchored archaeologically in Roman time, and supra-long continuous
Scandinavian pine chronologies representing a true dendrochronological projection
of the real time line. This exercise showed that Roman oak most probably is
conventionally dated too old by 218 years (ref.2).
Such a result has to be verified carefully with independent methods, therefore we
present the following astronomical study about the case.

Astronomical dating of Roman time, draft, 2016-02-27, Page 3 of 49
Astronomical prerequisites
Astronomy is demonstrably one of the oldest sciences, practised already by
prehistoric cultures. Babylonian and Greek astronomers were able to make
predictions about conjunctions and eclipses although they did not have a modern
model of the celestial mechanics. Modern astronomy makes exactly timed routine
predictions for various phenomena, and allows us to explore our solar system.
However, to refine the modern model by e.g. adding correction factors for the
retardation of Earth's rotational speed, it was necessary to consider historical
observations (e.g. ref.5). This work resulted in computer programs like the NASA
Eclipse Explorers and Eclipse Search Engines freely available on the NASA Eclipse
Web Site (ref.6).
This work also automatically placed cultures, which marked their carefully timed
observations with e.g. the regnal years of their rulers, on the continuous astronomical
time line. This is true for the Babylonians whose clay tablets with astronomical
observations written in cuneiform are still extant and span over eight hundred years
(about -730 to 75). This is also true for the Chinese, Japanese and Korean cultures
whose observations uninterrupted span over the same period and up to modern
times (-709 to 1575).
There were no real astronomical schools in Europe, except for Alexandria. The
Alexandrian scholars made carefully timed observations similar to the Babylonians.
Therefore Hipparchus (second century BC), Hero (first century AD), Ptolemy (second
century AD) and Theon (fourth century AD) are fixed on the astronomical time line,
though we do not know much about their lives. Ptolemy has a large collection of
Babylonian, Greek and Alexandrian observations in his Syntaxis (also known as the
Almagest), which convincingly demonstrates that antique observation reports and
modern retrocalculations are compatible. However, it has been disputed since long
time ago if Ptolemy's own reports in the Almagest are made from real observations or
if they are merely calculated. Most modern astronomers having dealt with the
problem admit that Ptolemy's systematic errors are puzzling. Their conclusions span
from suspicion of some "fiddling with the truth" to the accusation of conscious
scientific fraud (ref.7). Parts of Hipparchus' work are preserved in the Almagest, but
no original observation reports are extant.
To summarize, a true astronomical projection of the real time line has been
established and is readily available to the public in the form of Internet based
computer models. This also means that the starting situation for our astronomical
study is very similar to that for dendrochronology: we have to define a range of
astronomical observations chronologically related to Roman time and to check their
current dating against the established astronomical time line.

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Stocktaking of west Roman and related astronomical observations
The Roman time archaeological oak wood which we suspect is misdated by
dendrochronology is predominantly from Germany, France and England. Felling
years span from the last half of the first century BC to the fourth century AD
(conventionally), i.e. over the whole time of the West Roman Empire. Before that time
we have the Roman Republic, chronologically connected to the Empire via the
Roman time counts (AUC or the list of the Roman consuls) which are historically
ensured from about the fifth century BC. Chronologically connected are also the
Greek time counts, as Greece was annexed to Rome since the second century BC.
Astronomical observations dated within this synchronized "western dating fashion"
will therefore form the basis for this study. As we suspect that the whole West-
Roman/Greek historical complex might be conventionally dated too old by about two
hundred years, we will mark events within that complex retaining their nominal dates
but with an identifying prefix, e.g. RomAD 79 (AD 79) or RomBC 150 (150 BC). All
other (absolute) dates will be in NASA notation, that means the AD years are
counted from 1 up to present time, and the BC years are counted from -1 down
through the past. There is also a year -0 in order to facilitate arithmetic calculations.
In certain cases we set the prefix Astr to explicate that we mean the year number in
a continuous array (i.e. the astronomical time line), and not a nominal date.
So which dated astronomical records are still extant from ancient Europe? Richard
Stephenson writes (ref.5, ch.10.1):
Compared with the careful observations of similar age which are recorded on
the Late Babylonian astronomical texts, many of the eclipse records in
ancient Greek and Roman history come as something of an anticlimax.
Although numerous descriptions of both solar and lunar obscurations are
preserved in these sources, commencing as early as the seventh century
BC, most accounts are too vague to be suitable for investigating the Earth's
past rotation. The majority of writings which mention eclipses are literary
rather than technical, and include historical works, biographies and even
poems.
Many of the dated Roman records are panegyric. That means they were written to
emphasize the importance of a deceased prominent person and could therefore be
real or invented as well. The same applies to eclipse records of sun or moon in
connection with a determining battle. So it was not easy to find trustworthy, detailed
observations.
But then we found four observations in Pliny's "Natural History" which apparently
were made for scientific purposes and which were dated against the list of Roman
consuls. These observations have exactly matching retrocalculated solutions at the
proposed RomAD-dates.
Starting with Pliny's quadruple (his complete set of four timely coupled observations),
we will investigate if alternative datings are possible.

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1. Astronomical observations by Pliny in his Natural History, book II.
These are the four dated astronomical observations from Pliny the Elder's "Natural
History" (refs.8,9):
a. ... The eclipse of both sun and moon within 15 days of each other has
occurred even in our time, in the year of the third consulship of the elder
Emperor Vespasian and the second consulship of the younger.
b. ... The eclipse of the sun which occurred the day before the calends of May, in
the consulship of Vipstanus and Fonteius a few years ago, was visible in
Campania between the seventh and eighth hour of the day but was reported
by Corbulo commanding in Armenia as observed between the tenth and
eleventh hour.
The consul years above have been connected to:
• RomAD 71 as the year of the third consulship of the elder Emperor Vespasian
and the second consulship of the younger and
• RomAD 59 as the consulship of Vipstanus and Fonteius
For observation a. we are looking for a (without telescope) observable solar eclipse
at 15 days distance from an observable lunar eclipse, presumably in Rome or
Campania.
For observation b. we are looking for a solar eclipse occurring 12 years before
observation a. at April 30 (or new moon in May) and observable in Campania in the
afternoon and in Armenia somewhat before sunset.
The commonly agreed to datings and corresponding eclipses can be verified with the
NASA Eclipse Web Site (ref.6). These were a solar eclipse on 71 March 20, and a
lunar eclipse on 71 March 4. The solar eclipse with its magnitude of 80% was indeed
observable in Rome or Campania, but the lunar eclipse was only partial. The moon
just touched into the dark shadow of the earth. Moreover, the eclipse was 16 days
away from the solar eclipse and not 15 days as specified in Pliny's observation.
The solar eclipse fulfilling the conditions for observation b. took place on 59 April 30.
With help of the NASA Eclipse Web Site we also found an alternative set of eclipses
232 years later: the solar eclipse on 303 September 27 with a lunar eclipse on 303
September 12 with exactly 15 days distance and being total as seen with a naked
eye. The corresponding solar eclipse 12 years before occurred on 291 May 15. Read
more about the astronomical details in Appendix A.
With the problem of possibly having to remove some 200 years from our historical
time line, it is tempting to propose that Pliny actually lived in a time where he could
observe the alternative set of eclipses.
Though a drawback is that the solar eclipse on 291 May 15 appeared 16 days later
than stated by Pliny if he meant April 30. On the other hand, also May 15 may very
well correspond to the phrase "the day before the calends of May". The day before
the calends means the day before the start of a new lunar cycle in a lunar calendar.
As a solar eclipse implies that the moon is standing between the earth and the sun
this also implies the start of a new lunar cycle.
The consulship of Vipstanus and Fonteius corresponds to RomAD 59, see above. To
make RomAD 59 the same as year 291 we have to remove 232 years out of our
current historical calendar. That would imply that Pliny lived in Astr 255 to 311
instead as commonly agreed to in RomAD 23 to 79.

Astronomical dating of Roman time, draft, 2016-02-27, Page 6 of 49
Are there more dated astronomical records which have a solution 232 years later in
time?
2. The eclipse of the moon before the battle at Gaugamela
Several Greek and Roman writers recorded a lunar eclipse that occurred before the
battle between Alexander the Great's army and Persian forces at Gaugamela near
Arbela (todays Erbil in northern Iraq). The date of the battle is given by Arrian as
during the month Pyanopsion when Aristophanes was archon at Athens. This means
early in the autumn (October) RomBC 331 or 330 in our calendar. Plutarch mentions
that the eclipse preceded the battle by 11 days.
There was a large lunar eclipse on -330 September 20, but also a second one 232
years later on -98 October 6. Both eclipses would date the battle to October as Arrian
says, and both were visible in northern Iraq, but at different hours of the night. A
strange coincidence is the fact that the two solutions for Pliny's quadruple (see the
previous section) and the two candidates for the Arbela eclipse are offset by exactly
the same number of days: 232 (Julian) years + 16 days = 84754 days.
A timing of the lunar eclipse at Arbela and a second place is given by both Pliny and
Ptolemy. Both writers lived several centuries after Alexander. Therefore it is
impossible that they made the observations themselves. However neither writer
states the source for his timings and they give completely different hours of the night
for the event. The difference is fully three hours. Read more about the astronomical
details in Appendix B.
To summarize Appendix B, Pliny's timing for the lunar eclipse at Arbela is fully
compatible with the -330 event and just incompatible with the -98 event. However,
Ptolemy's timing is not compatible with either of the two events, especially not with
the -330 event which was already over at the time mentioned at Arbela. We might
wonder how it is possible that Pliny, who was not an astronomer, could have more
exact data than Ptolemy, who was a professional astronomer and had access to the
best data available (in Alexandria). This is even more strange as Pliny lived about
hundred years before Ptolemy. We actually might suspect that the timing given by
Pliny has been manipulated in some way.
Moreover, it seems that a Babylonian clay tablet mentioning the battle at Gaugamela
has been preserved by a rare coincidence. Two cuneiform tablet pieces (BM 36761 +
BM 36390) in the British Museum bear the official title "Astronomical Diary
concerning month VI and VII of the fifth year of Artašata who is called Darius". The
two pieces are from the same tablet, but they do not join. The references to the king,
his regnal year and month are missing but can be deduced from the astronomical
data given on the tablet.
To summarize the tablet: There was a battle 11 days after the lunar eclipse on -330
September 20. About three weeks after that battle the victorious "Alexander, king of
the world" entered Babylon. It is most likely that the battle at Gaugamela is described
in astronomical diary BM 36761 + BM 36390, and that this battle is dated by the
tablet to -330 October 1 as conventionally assumed. Read more about the details in
Appendix C.

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3. Comet observations in antiquity
As described in section "Astronomical prerequisites" above, the Chinese routinely
marked their carefully timed observations with e.g. the regnal years of their rulers.
Therefore Chinese history is dated on the continuous astronomical time line.
"Catalogs of comet observations" (e.g. ref.10) have been compiled in which you can
find for example the returns of comet Halley which occur every 77 years on average
and which are usually observable with the naked eye (ref.11).
A lot of Roman comet records exist as well (ref.12), however they are scanty and
diffuse which means that the Roman time complex is floating astronomically and has
an internal historical time line (which is a subject for interpretation). Unfortunately,
comet Halley is not suitable to check our hypothesis that Roman time is
conventionally dated 232 years too old, because 232 years is nearly a multiple of the
comet's average orbital period. The following table shows e.g. that a comet observed
in RomAD 142 could be related to either the 141 return of comet Halley as
conventionally assumed, or the 374 return if the 232-years-hypothesis is right.
Halley's comet
return ref.11
(astr. year)
Halley's comet
return in Roman context
(i.e. minus 232 years)
530 RomAD 298
451 RomAD 219
374 RomAD 142
295 RomAD 63
218 RomBC 15
141 RomBC 92
66 RomBC 167
-11 RomBC 244
-86 RomBC 319
-163 RomBC 396
-239 RomBC 472
We also have plotted the Roman comet observations in their historical context and
marked the return years for comet Halley on the time line, see Figure 1. There must
have been considerable "comet fever" in Rome when comet Halley was seen around
RomBC 165. After that sighting there are lots of comet observations during the next
four centuries, then the written sources go silent. It seems that all returns of comet
Halley between RomBC 165 and RomAD 218 have been observed in Rome, but
the reports are too scattered in time to be assigned to a particulary year. See
especially the return around RomAD 65.

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Figure 1: Roman comet observations in their historical context (RomBC/AD). The periodic returns of
comet Halley are marked in Roman context according to our hypothesis (blue arrow), or with their
astronomical date (red lozenge), see also the table above. The 188 return of comet Swift-Tuttle is
marked in Roman context with a red arrow and at the astronomical date with a blue triangle. Use the
magnifying function in your reader to see details.
But there was apparently also "non-Halley comet fever" in Rome (see the red arrow
with filled arrow head in the diagram above). Around the time for Julius Caesar's
assassination (RomBC 44, March 15) a new bright transient star was observed in
Rome. It is referred to in the contemporary literature as sidus Iulium (Julian
star/heavenly body) and Octavian, Caesar's adopted son and subsequently
Augustus, is said to have managed to launch the star or comet as a sign of his
father's divinity, thereby increasing his own power. The time of observation is
generally assumed to be the end of July RomBC 44 during the funeral games for
Caesar held by Octavian, when Caesar had been dead for more than four months.
However, a star appears on coinage already during Caesar's lifetime, and Nandini B.
Pandey concludes in her recent paper (ref.13):
Octavian, in other words, had no need to invent the sidus Iulium during the
funeral games that summer; the idea of Caesar’s divinity and its
representation by means of a star were already part of Roman cultural
discourse and were already circulating in numismatic form around the time of
Caesar’s death.
Figure 2: Silver denarius CAESAR IMP, minted in Rome by P. Sepullius Macer, January to February
44 BC. http://www.coinproject.com/coin_detail.php?coin=240586

Astronomical dating of Roman time, draft, 2016-02-27, Page 9 of 49
So an alternative interpretation of the sources could lead to the assumption that the
sidus appeared already in RomBC 45, perhaps during the games held by Caesar in
July 20 - 30 in honor of Victoriae Caesaris.
A lot has been written about this celestial phenomenon, which has been considered
alternately myth or reality until an almost matching comet was found in independent
Chinese astronomical records (ref.14). This comet got the denomination C/-43 K1,
and an inclination of about 110 degrees and a magnitude of about -4 (which means
visible in moderate daylight) were calculated. However, the time of observation in
China was not the end of July, but May 18 to June 16 Astr -43, which the authors
were quite troubled about. C/-43 K1 has apparently never returned, either its orbital
period is very long or it has disintegrated on its way.
According to our hypothesis that Roman time is conventionally dated 232 years too
old, Caesar died in 189 and the sidus was instead sighted in 189 or 188. Therefore
C/-43 K1 would have nothing at all to do with Caesar's comet, if we are right.
However, for the year Astr 188 (corresponding to RomBC 45 according to our
hypothesis), the Chinese records mention the appearance of a large "guest star" on
July 28 until mid-August. This guest star has been identified as Comet P/Swift-Tuttle
(ref.15), which has a mean orbital period of c.133 years and an inclination of 113
degrees. The Chinese records say that it was "as large as a vessel with a capacity of
three pints", a peak brightness of 0.1 mag (almost visible in daylight) has been
calculated for this apparition of the comet. Furthermore the modern authors interpret
that the description "as large as a vessel" could mean a nebulous appearance
without a tail, which seems to be characteristical for comet Swift/Tuttle. Contrary to
comet Halley, comet Swift-Tuttle is not always visible with the naked eye. In fact, the
188 return was by far the brightest in historical times, the comet was not observed
again until 1737. We have found no Roman report of Comet Swift-Tuttle at its
astronomical date (see the blue triangle in Figure 1).
To sum up, the Astr 188 apparition of Comet P/Swift-Tuttle seems to be a hot
candidate for Caesar's comet. It is bright and large, visible in the right celestial
location over Rome and appears at the right time of the year (July, which is Caesar's
birth month and named in his honor). Its appearance a few months before Caesar's
death resolves the discrepancy between numismatic evidence and written (later)
sources: it was probably Caesar himself, and not Octavian, who first used a star to
promote the divinity of the Julian family.
Finally we can mention that the Chinese records (ref.10) also provide a candidate for
the "Star of Bethlehem" if we slide Emperor Augustus and the birth of Jesus Christ
232 years towards our time. In November 236 a large comet was observed "in the
east". Do we need to say that it has been hard to find a suitable astronomical
phenomenon at the conventional place on the time line?
4. The eclipse of the sun before the battle at Coronea
Xenophon of Athens, said to have lived about RomBC 430 to 354, was a soldier and
historian. He is known for his writings on the history of his own times, the 4th century
BC, preserving the sayings of Socrates, and the life of ancient Greece. His
"Hellenica" is a major primary source for events in Greece from RomBC 411 to 362.

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Xenophon was later exiled from Athens, most likely because he fought under the
Spartan king Agesilaus II against Athens at Coronea during the Corinthian War
(source: Wikipedia, Xenophon).
Therefore it might be an eyewitness report when he writes in his "Hellenica" (ref.16):
Next day he crossed the mountains of Achaea Phthiotis, and for the future
continued his march through friendly territory until he reached the confines of
Boeotia. Here, at the entrance of that territory, the sun seemed to appear in a
crescent shape, and the news reached him of the defeat of the
Lacedaemonians in a naval engagement, and the death of the admiral
Peisander.
The same event is also reported by Plutarch in his "Life of Agesilaus" (ref.17):
Agesilaus now marched through the pass of Thermopylae, traversed Phocis,
which was friendly to Sparta, entered Boeotia, and encamped near
Chaeroneia. Here a partial eclipse of the sun occurred, and at the same time
news came to him of the death of Peisander, who was defeated in a naval
battle off Cnidus by Pharnabazus and Conon.
The solar eclipse appeared directly before the battle at Coronea. The Spartan king
Agesilaus II had been in Asia Minor to assist Greek settlements against the Persians.
Early in springtime, he was organizing troops in the vicinity of Thebe for a campaign
to the Asia Minor inland, when he was recalled to Greece for a war between Sparta
and Athens with allied. He left part of the troops with a governor in Asia Minor, and
rapidly marched with the rest via the Hellespont, Trace, Macedonia and Thessaly
towards Boeotia. Underway he got both good and bad news about already ongoing
acts of war. The year of the battle at Coronea is given as the second year of the 96th
Olympiad, and thus RomBC 395/4 in our chronology.
Figure 3: Map of Asia Minor and Greece showing relevant places and distances for the march of
Agesilaus II from Thebe to Boeotia.

Astronomical dating of Roman time, draft, 2016-02-27, Page 11 of 49
We are looking for an observable partial solar eclipse (magnitude >0.5) in the late
afternoon and visible at Chaeroneia. In the late afternoon, because the reports
implies that it was visible when the troops were already encamped after a long day's
march.
Stephenson considers the annular solar eclipse of RomBC 394 August 14 as a
candidate (ref.5, ch.10.3). That eclipse had the magnitude 0.91 at Chaeroneia, but it
was a forenoon event. The discrepancy regarding the time of observation is noted by
Stephenson:
Although the Sun would be high in the sky at the time, Agesilaus would be
marching in a south-easterly direction, facing into the Sun, so that the eclipse
would be more easily noticeable.
But there is actually another objection against this eclipse: it happened in August. Did
it really take about six months to march the about 1000 kilometers from Thebe to
Chaeroneia? Remember that Agesilaus had not yet begun his campaign against the
Persians when he was required to set off for Greece ("the season verged on spring",
ref.16). Paul Cartledge (ref.18) mentions that an army with infantry and impedimenta
would have needed three months to move about 3000 kilometers at the time of
Alexander the Great. About 500 kilometers could be covered in twelve days if forced
march was required.
Within the period -500 to -100 there are 17 partial solar eclipse in the late afternoon
visible at Chaeroneia (ref.6). If we redate the second year of the 96th Olympiad
according to our hypothesis 232 years towards our time, we arrive at -162/1. Among
our 17 candidates we then find the solar eclipse of -162 March 15. The magnitude
was 0.76 and it started at about 5 o'clock in the afternoon, with the maximum one
hour later when the Sun was five degrees above the horizon. The crescent shape
must have been clearly observable with the naked eye.
5. A solar eclipse observation mentioned by Plutarch
This is the report of an eclipse of the sun from Plutarch's dialogue "On the Face in
the Moon" (ref.19, chapter 19):
Now, grant me that nothing that happens to the sun is so like its setting as a
solar eclipse. You will if you call to mind this conjunction recently which,
beginning just after noonday, made many stars shine out from many parts of
the sky and tempered the air in the manner of twilight. If you do not recall it ...
There is no information neither where this eclipse was observed, nor when it was
observed. But the above statement is made by a Lucius who most probably lives in
Rome. Moreover, the appeal to remember is addressed to all participants of the
dialogue, who apparently are from different places in the Roman Empire such as
Italy, Greece and Egypt.
If we do not reject the report as a product of Plutarch's imagination as Robert Newton
(ref.20) does, we should look for an - at least - annular solar eclipse with a maximum
at noon over at least one of the urban centers of the antique world during the adult
lifetime of Plutarch.
Stephenson and Fatoohi (ref.21) consider four possibly total solar eclipses in the
central or eastern Mediterranean during the assumed lifetime of Plutarch (RomAD 45
to 120), and argue that the observation should be connected with the solar eclipse of

Astronomical dating of Roman time, draft, 2016-02-27, Page 12 of 49
71 March 20 over Greece. However, the maximum of this eclipse was at 11:00 local
time. The report saying "beginning just after noonday" is then not a very exact
description of the eclipse. Furthermore, the totality of this eclipse would have been
visible only in Athens and the south-eastern part of Greece, which dramatically limits
the number of participants in the dialogue who could have been eye witnesses and
would remember the event. As a matter of fact, there was no solar eclipse during the
whole first century AD which came even close to totality in Rome or Campania.
According to our 232 years hypothesis, Plutarch would have lived in the period 277 to
352 and we would expect a major solar eclipse over the Mediterranean within that
period. The annular eclipse of 334 July 17 was an event at noon visible from Rome,
Campania, southern Greece and Alexandria. It is actually a much better match
towards the observation in the dialogue than the one suggested conventionally.
"Everybody" would have seen it, and even though its obscuration was only about
95%, Venus was visible close to the eclipsed Sun for several minutes. We may
actually wonder why there are no reports of this dramatic eclipse with its "true" date.
The only instance where we have found that this eclipse is mentioned is in the
Mathesis, a book on astrology by Firmicus Maternus (ref.22). Read more about the
astronomical details in Appendix D.
Initial discussion
The five Roman/Greek reports of astronomical events investigated above have all
been used by others to prove the validity of the conventional chronology. Even
though there are two solutions with 232 years offset for both Pliny's quadruple (1.
above) and the lunar eclipse before the battle at Gaugamela (2. above), the
Babylonian clay tablet dating that battle seems to tilt the scales in favour of the
conventional solution. However, if our dendrochronological results are correct,
something must be wrong with the astronomical records in some way. Ultimately we
have to decide which dating method we trust most. For the time being we rely on
dendrochronology as this method is completely independent of historical
considerations.
So what could be wrong with the record on the clay tablet found in the ruins of
Babylon in 1880 (ref.23)?
The tablet is an astronomical diary, and it is a copy of an older damaged tablet.
There is no doubt that the astronomical record describes the situation in the autumn
of Astr -330, but the political record is a bit vague. The only explicite name
mentioned is "Alexander", neither "Darius" nor "Gaugamela" or "Arbela" are
preserved. The tablet could therefore describe another battle and another victorious
Alexander.
However, the most plausible explanation (for the case that we are right) is that the
scribe chose a set of suitable astrological omens when he handled the record of a
decisive battle with far-reaching consequences for his society (see the commentary
in ref.34). This he could achieve in two ways: either he could add the political record
to a suitable existing astronomical record, or he could fabricate (i.e. retrocalculate)
the entire astronomical record. That the Babylonians were fully capable of doing so is
proven on the same clay tablet: the equinox on the twenty-first day was certainly
calculated as the astronomer comments "I did not watch". And the solar eclipse on
the twenty-ninth day was expected after sunset (!) and moreover impossible to see in
Babylon.

Astronomical dating of Roman time, draft, 2016-02-27, Page 13 of 49
If already the Babylonians had these skills, also later ancient astronomers could have
been experts in retrocalculation. This is exactly what Robert Newton (ref.24) suspects
regarding Claudius Ptolemy and his Syntaxis (Almagest). Newton claims that all
Ptolemy's own and most of the earlier "observations" made by others in the Syntaxis
were fabricated. He goes so far that he states in his Final Summary:
It is clear that no statement made by Ptolemy can be accepted unless it is
confirmed by writers who are totally independent of Ptolemy on the matters in
question. All research in either history or astronomy that has been based
upon the Syntaxis must now be done again.
If this is valid for the Almagest, which is regarded as the most eminent support for our
conventional chronology, it could as well be valid for Pliny's astronomical statements
in his "Natural History". So what makes even modern astronomers convinced that the
conventional solution is correct? First there is the Arbela eclipse timing (see 2.
above), and second there is one explicite date in Pliny's quadruple (1. above) which
clearly point out the conventional solution as the right one. These two statements
happen to appear in the same passage (ref.9, ch.72):
Consequently inhabitants of the East do not perceive evening eclipses of the
sun and moon, nor do those dwelling in the West see morning eclipses, while
the latter see eclipses at midday later than we do. The victory of Alexander
the Great is said to have caused an eclipse of the moon at Arbela in the
second hour of the night while the same eclipse in Sicily was when the
moon was just rising. An eclipse of the sun which occurred the day
before the calends of May, in the consulship of Vipstanus and Fonteius
a few years ago, was visible in Campania between the seventh and
eighth hour of the day but was reported by Corbulo commanding in
Armenia as observed between the tenth and eleventh hour: this was
because the curve of the globe discloses and hides different phenomena for
different localities. If the earth were flat, all would be visible to all alike at the
same time; also the nights would not vary in length, because corresponding
periods of 12 hours would be visible equally to others than those at the
equator, periods that as it is do not exactly correspond in every region alike.
What if a later copyist with astronomical skills made some "minor changes" in that
passage for some reason? We get a hint that something is wrong when Pliny about
hundred years before Ptolemy gives a far better timing of the eclipse at Arbela.
Maybe Ptolemy's "Geography" contains some genuine information about the eclipse
(i.e. that it was seen around midnight), while Pliny's "Natural History" has been
amended with later "improved" information?
If our dendrochronological results are true, we would indeed expect inconsistencies
in e.g. the Almagest. The existence of two solutions for Pliny's quadruple, of which
one confirms our calendar and the other one is compatible with our dendro results,
also points at astronomy as the method chosen to inflate the Christian era. But who
was capable to make such comprehensive retrocalculations? Without doubt the
astronomical school of Alexandria in late antiquity. Maybe some Arabian astronomers
in medieval times. European astronomers not before Copernicus, i.e. in the
Renaissance. But at that time the AD count had already been in use for centuries
and copies of the Almagest were widespread in Europe and the Islamic world.
However, the 232 years offset apparently was invented already in Babylon, if we are

Astronomical dating of Roman time, draft, 2016-02-27, Page 14 of 49
right. It is possible that the phenomenon was merely "rediscovered" as an elegant
solution to a special problem by later colleagues e.g. in Alexandria.
This argumentation eventually leads to the conclusion that the offset not necessarily
has to be 232 years, any number might be viable. However, the number has to be
fairly close to 218 years which is the dendrochronological error, otherwise historians
would have rejected the calibration of the Roman dendro complex which was done in
the early 1980s (see the discussion in Appendix E). But the dated astronomical
reports which have no conventional solution (3. and 4. above), especially Caesar's
comet which was impossible to fabricate, strengthen the hypothesis that the offset
indeed is 232 years.
Discussion of historical timing problems which support our hypothesis
But there are actually more indications that we might be right.
First there is the argument originating from the Illig group that the Gregorian
calendar reform possibly does not account for all the years said to have elapsed
since the introduction of the Julian calendar (ref.1). This argument has been rejected
by mainstream historians with the reference to Gregorius: the intention of his
calendar reform was only to restitute the conditions at the Nicaea Council and not at
the introduction of the Julian calendar 370 years before. However, because of scanty
sources it is not possible to decide in favour of either side.
But we do not have to go back to Julius Caesar. Slightly before the Nicaea Council,
Anatolius of Alexandria apparently observed the vernal equinox. From that we can
conclude that the historical time line indeed counts 200 to 300 years too much
between 325 and 1582. Read about the details in Appendix F.
Then there are references to a large civilization far to the west from China in the
Chinese historical records beginning during the later Han period. This civilization is
called Da Qin and has been identified as being either Rome, the Roman Empire or
the Roman eastern provinces.
Some points of special interest about Da Qin from the Hou Han Shu (ref.25a, sect.
11/12) for the time 25 to 220 are as follows:
• The seat of government is more than a hundred li (41.6 km) around. In this
city are five palaces each ten li (4.2 km) from the other.
• Their kings are not permanent. They select and appoint the most worthy
man. If there are unexpected calamities in the kingdom, such as frequent
extraordinary winds or rains, he is unceremoniously rejected and replaced.
The one who has been dismissed quietly accepts his demotion, and is not
angry.
• They make gold and silver coins. Ten silver coins are worth one gold coin.
• In the ninth yanxi year [166 CE], during the reign of Emperor Huan, the king
of Da Qin, Andun, sent envoys from beyond the frontiers through Rinan
(Commandery on the central Vietnamese coast), to offer elephant tusks,
rhinoceros horn, and turtle shell. This was the very first time there was
[direct] communication [between the two countries]. The tribute brought was

Astronomical dating of Roman time, draft, 2016-02-27, Page 15 of 49
neither precious nor rare, raising suspicion that the accounts [of the ‘envoys’]
might be exaggerated.
These are quite fantastic statements. A circumference of about 40 km would mean a
city area of about 130 km2, which is a tenth of the total urban area of modern Rome,
or a third of the total urban area of modern Stockholm. So what the annalist most
probably meant was that the city was very large. But what does he mean by "their
kings are not permanent"? And he actually gives a name for the king of Da Qin at or
slightly before 166: Andun, which could refer to the European name Anton.
John Hill, the translator of the Hou Han Shu and Weilue, gives a lot of notes and
comments to the different statements. Of course he strictly presupposes that the year
166 is the same in both China and Rome. The statement of the five palaces is
uncommented, but he comments the point about the non-permanent kings as follows
(refs. 25b and 25c #11.18):
This appears to be nothing more than a fabulous story told of an ideal
country far-away and is reminiscent of many such stories told by early
European travellers to distant lands.
He comments the statement "ten silver coins are worth one gold coin" with the
remark that this probably refers to the Roman exchange rate of silver to gold which
had been 10:1 at the time of Alexander the Great and hundred years later, and which
was about 11:1 at Pliny's time (refs. 25b and 25c #12.2).
Finally, the king of Da Qin in the year 166 has to be Emperor Marcus Aurelius
(RomAD 161 to 180) who was a member of the Nerva-Antonine dynasty and had the
by-name Antoninus.
Now, what happens if Roman time is offset (i.e. conventionally dated too old) by 232
years? In that case the year 166 in China would be the same as RomBC 67 and we
are historically not in the Roman Empire but in the Roman Republic, eight years
before Julius Caesar becomes consul for the first time. There is no king but every
year two new consuls are elected for the highest political office.
Prominent Roman families compete for the political power, among them the Antonii
whose most famous member is Mark Antony, but he will enter the political stage first
about two decades later. Maybe it was a member of this family who sent an envoy to
the remote China with gifts which were regarded as "neither precious nor rare"?
What about the "five palaces" in Rome? Republican Rome had no royal palace, but
the Capitolium was regarded as the citadel and religious center of the city. Here the
Tabularium was located, holding the Roman records of state. Besides the Capitolium,
the city within the Servian walls was divided into four admiminstrative regions
(regiones quattuor, ref.26). The division into four regions remained in force until the
reorganisation of Augustus in RomBC 7.
Also the silver to gold exchange rate of 10:1 points at information about the Roman
Republic rather than the Roman Empire.
There should be more historical inconsistencies of this kind, and we actually found
some more. The report of Plutarch's solar eclipse cited in 5. above continues as
follows (ref.19, chapter 19):
If you do not recall it, Theon here will cite us Mimnermus and Cydias
and Archilochus and Stesichorus besides and Pindar, who during eclipses

Astronomical dating of Roman time, draft, 2016-02-27, Page 16 of 49
bewail 'the brightest star bereft' and 'at midday falling' and say that the beam
of the sun 'is sped the path of shade'; and to crown all he will cite Homer,
who says 'the faces of men are covered with night and gloom' and 'the sun
has perished out of heaven' speaking with reference to the moon and hinting
that this naturally occurs when waning month to waxing month gives way.
The Theon mentioned here is recognized as the literary expert of the dialogue, and
he is explicitely said to live in Egypt (ref.19, chapter 25). If the solar eclipse discussed
is the one of Astr 334 as proposed in 5. above, this Theon could be identical with the
young Theon of Alexandria, the man from the Mouseion who later reported a unique
solar eclipse. This eclipse could be retrocalculated to Astr 364 (ref.5) and therefore
placed Theon on the astronomical timeline.
Even more intriguing is the fact that Ptolemy, working in Alexandria, refers to a
"Theon the mathematician" making astronomical observations in Alexandria, in his
Almagest. As Ptolemy's lifetime is assumed to be RomAD c.85 to 165, and the
Almagest (his earliest work) was finished about RomAD 150, this Theon is assumed
to be Theon of Smyrna. But Theon of Smyrna was rather living in Smyrna instead of
Alexandria, and he was not known to be an outstanding astronomer (ref.7).
However, if we redate Ptolemy's lifetime with 232 years according to our hypothesis,
he would have lived c.317 to 397 and thus been contemporary and colleague with
Theon of Alexandria (c.335 to 405). His Almagest (redated c.382) could have
referred to Theon's observations, and Theon could have written his commentary on
the Almagest after the latter was finished.
Here is another indication that we might be right: Geminos was a Greek astronomer
and mathematician. Recently, a complete English translation of Geminos' only
surviving work "Introduction to the Phenomena" has been published (ref. 27).
Geminos wrote the "Introduction" as a textbook for beginning students of astronomy.
The book is nowadays considered to be written in the first century BC, that means
the period between Hipparchus and Ptolemy. Geminos mentions Hipparchus as a
forerunner, but he does not mention Ptolemy. But Geminos also mentions Hero of
Alexandria as a forerunner, which seems to be a problem. The following is a direct
citation from section 6 of the introduction of the new publication:
One minor problem with dating Geminos to the first century BC involves his
mention of Hero of Alexandria in fragment 1. The dating of Hero has been
controversial, with suggested dates from the middle of the second century
BC to the middle of the third century AD. In Dioptra 35, however, Hero
mentions a lunar eclipse observed simultaneously in Alexandria and Rome.
Although Hero does not mention the year of the eclipse, he is detailed about
its other circumstances: 10 days before the vernal equinox, 5th seasonal
hour of the night at Alexandria. Neugebauer [ref.36] has shown that these
circumstances were satisfied by only one lunar eclipse between about -200
and +300, namely that of March 13, AD 62. If Hero used an eclipse of recent
memory, we must place him in the second half of the first century AD. Thus,
if the dating of Geminos to the first century BC is correct, we must suppose
that Proklos or a later copyist interpolated the name of Hero in fragment 1.
Hipparchus was a Greek astronomer and mathematician said to have lived about
RomBC 190 to 120, because Ptolemy attributes to him astronomical observations in
the period from -146 to -126 in his Almagest. As mentioned above, Geminos names

Astronomical dating of Roman time, draft, 2016-02-27, Page 17 of 49
both Hipparchus and Hero as forerunners, which means that Hero even could have
been contemporary with Hipparchus. This has been considered by historians, and
this makes the late dating of Hero controversial. But maybe we should instead
dispute the dating of Hipparchus in the Almagest.
If Hero would be fixed on the absolute astronomical time line because of his unique
observation, while Hipparchus and Geminos are placed on the relative historical time
line, our 232-years offset would make Hipparchus and Hero contemporary living in
the second half of the first century AD, while Geminos would have lived in the second
half of the second century AD and had both as forerunners.
Discussion of the "Who's done it, and why?"
With combined dendrochronological and astronomical evidence we now dare to
propose that the Christian era was prolonged by 232 years by means of astronomical
retrocalculation. This was a qualified and elegant manipulation most probably made
by a professional astronomer while there still were astronomers left, that means in
late antiquity in Alexandria.
If we assume that the prank originated from Alexandria, the most convenient point of
time to manipulate the timeline would have been in connection with the "invention" of
the Christian era. The AD count as we know it was used for the first time in the early
8th century by the Anglo-Saxon historian Beda Venerabilis. He used the Christian
era which was introduced by the Scythian monk Dionysius Exiguus in 525, the year
which he stated was the "present year" and "the consulship of Probus Jr.", as well as
"525 years since the incarnation of our Lord Jesus Christ" (ref.28). Dionysius does
not tell us how he arrived at that synchronization, but most likely he had the
knowledge from some predecessor. At this point we turn our heads towards
Alexandria.
Alden Mosshammer (ref.29) suggests that the actual date for the invention of the
Christian era was around 412 when Panodorus of Alexandria, maybe together with
Annianus, introduced the Alexandrian world era. This world era is synchronized with
the Byzantine world era and with the Roman year count in the same way as our
Christian era. It has been disputed whether Dionysius Exiguus knew about
Panodorus' synchronization, but Mosshammer suggests (as others long time before
him have done) that Dionysius merely adopted the Christian era invented in
Alexandria and introduced it to the west.
The Alexandrian world era was never adopted in the Byzantine Empire. Here the
Byzantine world era was introduced and came into use around 630. Between this
date and the invention of the almost identical Alexandrian world era around 412 are
about 220 years, a remarkable number indeed. So, who was Panodorus and when
did he actually live?
We have only second hand information about Panodorus, by the Byzantine chronicler
George Syncellus who lived in the 8th century AD. He informs us that Panodorus and
Annianus were contemporaries who worked in Alexandria in the time of emperor
Arcadius and Theophilus, the 22nd archbishop of Alexandria and Egypt, who died in
412. Syncellus also says that Panodorus used the "Astronomical Canon", i.e. the king
list used in Ptolemy's Almagest, to place Jesus' birthday on the historical time line.
But as Alden Mosshammer remarks (ref.29, p.359):

Astronomical dating of Roman time, draft, 2016-02-27, Page 18 of 49
Elsewhere, the name of one ‘Panodorus of Egypt’ appears only in a
topography of Constantinople attributed to the fifteenth-century historian
George Codinus. The author (3. 34) cites this Panodorus for an explanation
of how the place called Phocolisthon received its name. Panodorus had said
that the emperor Phocas slipped (olisthesai) from his horse at that place.
Since Phocas did not become emperor until 602, either the attribution of the
story to Panodorus is false, or the author knew of a diffrent Panodorus.
With our 232-years hypothesis, these two Panodoruses were one and the same
person. He lived in the beginning of the 7th century around the time for the
introduction of the Byzantine world era. In West-Roman context he would have lived
at the end of the 4th century when he invented the Alexandrian world era.
What happened in Alexandria around RomAD 400? After having been famous for
"pagan" philosophy and sciences, Alexandria became a center for Christian theology.
A lot of Church Fathers were living there at that time. Libraries were closed and
destroyed, in RomAD 391 all pagan temples were destroyed. The most fiery
theological debate of that period was about if Jesus was God or created by God
(Arian controversy). The numbering of the years since Diocletian came into use as
the chronological reference.
In RomAD 367 the bishop of Alexandria, Athanasius, defined which books should be
included in the New Testament as we know it today. At about the same time, the
gnostic gospels, giving a somewhat different interpretation of Jesus' life and death,
had to go underground at Nag Hammadi. This means, in the true sense of the word,
that a library of non-canonical books was sealed in a large jar and buried in the
Egyptian soil until a farmer recovered it in 1945.
What happened in the Byzantine Empire around 630? Heraclius became emperor
after Phocas in 610. He defeated the Sasanian empire in 628, but was not able to
stop the Muslim expansion which started directly thereafter. Heraclius replaced Latin
with Greek as the language of administration, and about the time of his reign the
Byzantine world era became the official year count.
Arianism was still present in remote parts of the Empire until the late 7th century, and
also Islam was regarded as some kind of Arianism.
With the hypothese that RomAD 412 in Alexandria is the same year as 644 in
Constantinople, Arianism gets a quite dynamic development. It took only about one
hundred years until Islam emerged possibly as the result of a theological controversy.
The Christian church reacted with a sharp persecution of all kinds of heresy, and with
a strict consolidation of the scriptures. A new paschal canon and time count was
introduced as well. As (most probably) Panodorus says (ref.29, p.368):
Now that I have scientifically solved the ambiguous deeper meaning of the
Chaldeans, I have considered it necessary first to interpret the events before
the teaching of the Watchers up to the 165th year of Enoch in the year 1286.
Next I proceed to outline the chronological sequence from Adam up to the
20th year of Constantine, so that by identifying according to their nation the
kings who held dominion, I may show in my computation a total of 5816
continuous years. Moreover, on the basis of the men whose genealogies
have been traced in divine Scriptures from Adam up to Theophilus, destroyer
of idols, the praiseworthy twentysecond archbishop of Alexandria, Egypt, and
the two Libyas, I shall compute the chronology, and set forth the total
number of years as 5904 - this so that both the heresiarchs and pagans,

Astronomical dating of Roman time, draft, 2016-02-27, Page 19 of 49
wise in their self-conceit, may find no basis of support in our divine
Scriptures.
This last sentence sounds almost like a policy statement. Maybe Panodorus'
computations also included a manipulation of the historical time line to try to make
the Christian religion look older than it was in order to gain legitimacy in relation to
the young Islam. In that case he almost certainly acted on the command of the
highest level of power, and the truth was of course of lesser importance.
The New Testament was not the only book to be "canonized". Ptolemy's Almagest
was definitely a candidate for such a manipulation. As this work appears now, it
preserved the orthodox view of the geocentric hypothesis for another millennium,
though the heliocentric hypothesis was already formulated by Aristarchus several
centuries before Ptolemy. Robert Newton (ref.24), recognizing that most
measurements in the Almagest were fabricated for some reason, identified also this
fact and tried to answer the question about the motive:
For example, it is possible that Ptolemy was a devotee of some religious
fanatic who thought that he had divined the true system of the world, and that
all other truth was unimportant.
What Newton did not suspect was a manipulation of the Christian era time line,
because he had no independent scientific hypothesis to prove that. However, he
gives a detailed description of the modus operandi for such a manipulation (ref.24,
page 374):
It is also important to realize that Ptolemy does not need an authentic king list
in order to give a year in the Babylonian fashion. Even if his king list is
fabricated, he can still use it in order to assign a specific year of a specific
king to his fabricated eclipse record.
Now let us see what happens to a modern historian or chronologist who
studies Ptolemy's eclipse records. He sees that there is a list of kings and
their reigns. He also sees that Ptolemy dates a lunar eclipse in the first year
of Mardokempad, for example, on a certain month and day in the Egyptian
calendar, at a certain hour on that day, and he states the fraction of the moon
that was shadowed during the eclipse. The historian uses Ptolemy's king list
to find the year in our calendar and he uses the Egyptian month and day to
find the complete date in our calendar. He then finds by astronomical
calculations that there was an eclipse on that date, that it came close to the
hour that Ptolemy states, and that the stated amount of shadowing is also
close to correct. This agreement between Ptolemy and modern astronomy
happens not just once but seven times.
The historian or chronologist naturally concludes that there is overwhelming
evidence confirming the accuracy of Ptolemy's king list, and he proceeds to
use it as the basis for Babylonian chronology. Yet there is no evidence at all.
The key point is that there may have been no Babylonian record at all.
Ptolemy certainly fabricated many of the aspects of the lunar eclipses, and
he may have fabricated all of them. When he fabricated them, it did not
matter whether he used a correct king list or not. Any king list he used,
regardless of its accuracy, would seem to be verified by eclipses.
Newton identifies the perpetrator as somebody calling himself Ptolemy. As an
alternative most likely motive to the falsifications in the Almagest he proposes that

Astronomical dating of Roman time, draft, 2016-02-27, Page 20 of 49
Ptolemy maybe wanted to be known as a great astronomer but did not have the
ability to live up to that goal. Therefore he replaced ability by fraud.
With our hypothesis this motive becomes unlikely, because the manipulations were
not limited to the Almagest. They involved the whole astronomical literature of
antiquity, which was either amended as in the case of Pliny's "Natural History", or
eliminated as in the case of the entire work of Hipparchus.
The numbering of the years since Diocletian (Diocletian era, starting at RomAD 284)
also deserves some comments. This is a year count specific for Egypt and known to
the west only through its use in the Easter tables of Alexandria. In Egyptian papyri,
the designation of a year by reference to Diocletian appears in horoscopes for
birthdates ranging from year 21 to 224 (ad 304/5–507/8). Since a horoscope may be
cast some time after a person’s birthdate and even for persons who are deceased,
the horoscopes do not in themselves tell us how early the dating system came into
use (ref.29, page 26). In other words we experience here another example of
astronomical recalculation.
With our hypothesis, this era was designed to number the "invented" years between
RomAD 412 and 644. With the adoption of the Byzantine world era it was no longer
needed thus it became possible to abandon the Diocletian era. This is exactly what
Dionysius Exiguus did in his Easter Tables (ref.28):
... we did not wish to include in our circle the memory of an impious and
persecutor, but we chose above to mark the time from the year of the
incarnation of our Lord Jesus Christ.
However, the Diocletian era survived as the "Era of Martyrs" and is today still used
within the Coptic Orthodox Church. If we are right and there are invented years in our
calendar, we have to reduce 284 years by 232 and arrive at year 52 of the Christian
era as the starting point of the Coptic calendar. This year might be a mere
coincidence, but maybe it marks something that is worth commemorating. For
example the death of Mary, Jesus' mother.
The practice to fabricate astronomical observations continued even after Ptolemy
and Panodorus. There are for example seven eclipse records in the chronicle written
by Hydatius, bishop of Aquae Flaviae (modern Chaves, Portugal), in the fifth
century AD (ref.30). We can verify these records with e.g. the NASA Eclipse Web
Site, but does that verification really say that Hydatius lived at that time and made the
observations? Or did somebody only pretend that Hydatius lived at that time, in order
to "plant" the list of Roman consuls from RomBC 509 to RomAD 468 which is
appended to the chronicle?
The astronomical records in the chronicle were actually written down carelessly so
that it becomes apparent that they were merely calculated or copied or both (ref.30,
vol.1, p.92):
The dates for the solar and lunar eclipses can be verified by computation and
the results of computer analyses appear in Table 4. Only two dates are
incorrect out of seven reported. The first is the solar eclipse of Friday 19 July
418 which Hydatius records as Thursday 19 July 417. This eclipse was a
very well known occurrence and appears in a number of other sources,
though with no day (see Table 4). Hydatius mistakenly placed the entry in the

Astronomical dating of Roman time, draft, 2016-02-27, Page 21 of 49
wrong year (417) and calculated the missing day of the week based on that
year. This explains an accurate day of the week for a mistaken year, a fact
which otherwise would be an amazing coincidence.
MS B records the date of the lunar eclipse of 26 September 451 as 27
September 451. This error is likely just the result of textual corruption (the "I"
of "VI" has been lost) and the figure has been corrected in my edition.
Hydatius also gives a detailed comet report which has been connected to the 451
apparition of Comet Halley (ref.30, P.270):
... appears in the eastern sky on 18 June 452 (date should be 451). From 29
June visible in east at dawn and in west after sunset (this parihelion
confirmed by [R. Stephenson]). From 1 August appears only in the western
sky.
Richard Burgess (ref.30, p.93) notes that Hydatius gives the wrong year "for some
reason". With our hypothesis, this reason would be that Hydatius instead watched the
684 apparition of Comet Halley (684 -232 = 452, see also 3. above on "Comet
observations in antiquity" ).
The Chinese annals (ref.10) record both apparitions of the comet, the one of 451
around the middle of May and the one of 684 around the beginning of July. This
gives a satisfactory fit with Hydatius' report and would mean that he lived
astronomically in the 7th century, but in the historical context of the 5th century.

Astronomical dating of Roman time, draft, 2016-02-27, Page 22 of 49
Final conclusions
The chilling result of this study is that, except for some comet observations, we
cannot rely on astronomical observations made in "western" antiquity to confirm the
validity of our chronology. Every single record might have been fabricated because
the ancient astronomers were fully capable to do so. For that reason our 232-years-
hypothesis will never be more than a hypothesis.
However, we can conclude from dendrochronology that the size of the calendar error
has to be slightly more than two hundred years. Eventually we also found that the
232 years offset gives acceptable results both regarding astronomical observations
without conventional solutions (3., 4, and 5. above), and regarding the revised
synchronization of the Roman dendro complex with history as described in Appendix
E.
This means that we have to rely, for the time being, almost solely on
dendrochronology to trace the truth. Carefully applied, dendrochronology has a
resolution of one year and is completely independent of other dating methods and
historical considerations. As Pearce Paul Creasman (ref.31) puts it regarding the
Egyptian chronology:
Presently, Egyptology (along with all related fields that draw from Egyptian
chronology) has only the option to fit chronology into the combined historical
and archaeological record, a source of considerable debate and confusion.
Dendrochronology can stand alone and independent, as an arbiter of time
into which the historical record can be placed.
Or as Mike Baillie puts it more generally: Trees don't lie.
But can we be sure that the scientists, who listened to the trees when the long
European oak chronologies were assembled, got the message right? Though doubts
about that were expressed almost immediately, essential tree-ring measurement data
sets were kept secret. Among them were almost all chronologies used to confirm the
continuity and length of the Christian era. This has effectively prevented any
independent validation and still today far from all data sets are publically available
(see ref.2).
Sadly, this is completely at odds with the ego image of the association of
dendrochronologists (ref.32):
Accordingly, our scientific activities have become a social process and our
results have become public knowledge open to criticism, as well as
verification or falsification. These are the minimum requirements for a
discipline to be accepted as a science. As long as we dendrochronologists
feel part of such a scientific community (as a voluntary association), we
submit ourselves to strict social control that ensures the reliability of our
scientific statements.
To summarize: Our astronomical studies suggest that the Christian era counts 232
years too much between the beginning of the 5th century and the middle of the 7th
century. This period coincides with what is called the Migration period. However, 232
years too much in the historical time line does not mean that a certain range of years
can be deleted as a whole. History which once was expanded to fill the invented

Astronomical dating of Roman time, draft, 2016-02-27, Page 23 of 49
years has to be reintegrated into history before and after the phantom period. We use
the following two examples to explain what we mean.
Example 1: Panodorus of Alexandria is regarded as the originator of the Alexandrian
world era around 412. As a chronicler, he also appears in the first part of the 7th
century, i.e. some 200 years later.
Example 2: The 5th century in Roman context saw the final decline of the West-
Roman empire. According to our hypothesis, the crash came with the start of the
Arabian expansion after 630. This has been postulated by Henri Pirenne (ref.33),
who rejected that the collapse of the West-Roman culture and economy was caused
by the barbarian invasions during the 4th and 5th centuries. Instead, late antiquity
ended in the west following the Muslim conquest of north Africa, when the east-
western trade routes in the Mediterranean were cut off.
Our dendrochronological studies (ref.2) suggest that oak construction wood, which
is archaeologically anchored in West-Roman time, is dated too old by 218 years. Our
discussion above indicates that West-Roman history is possibly misdated by exactly
232 years. The difference, 14 years, corresponds to the current dendrochronological
misdating within the Roman context. This means that all current dendrochronological
dates within the Roman time complex have been given 14 years too young. In
Appendix E we have shown evidence for an error of that size. According to our
interpretation, the offset is caused by an improper synchronization of the Roman
dendro complex towards Roman history which was done more than thirty years ago.
Our 14 years correction will reestablish Tacitus' chronological trustworthiness which
has been doubted because the generally accepted dendrochronological dates are
not always compatible with Tacitus' writings.
For this reason, if for no other, dendrochronologists should start investigating our
claims and prove what ultimately is the truth.
Finally, we can conclude that it is quite likely that Heribert Illig and Hans-Ulrich
Niemitz were right when they postulated a "phantom time" between antiquity and the
Renaissance. Their observation and claim, that the Gregorian calendar reform does
not account for all the years said to have elapsed since the introduction of the Julian
calendar, appears to be right (see Appendix F).
However, in this paper, in ref.2 and at our web site cybis.se/dendro we have
presented evidence for both the length of the phantom time and its position on the
time line which is different to what Illig and Niemitz have claimed. Therefore also our
suggestions for who has done the calendar manipulation and why and how are
completely different.

Astronomical dating of Roman time, draft, 2016-02-27, Page 24 of 49
Appendix A: Astronomical observations by Pliny in his Natural History, book II.
These are the four dated astronomical observations from Pliny the Elder's "Natural
History" (refs.8,9):
1. ... The eclipse of both sun and moon within 15 days of each other has
occurred even in our time, in the year of the third consulship of the elder
Emperor Vespasian and the second consulship of the younger.
2. ... The eclipse of the sun which occurred the day before the calends of May, in
the consulship of Vipstanus and Fonteius a few years ago, was visible in
Campania between the seventh and eighth hour of the day but was reported
by Corbulo commanding in Armenia as observed between the tenth and
eleventh hour.
The consul years above have been connected to:
• RomAD 71 as the year of the third consulship of the elder Emperor Vespasian
and the second consulship of the younger and
• RomAD 59 as the consulship of Vipstanus and Fonteius
For observation 1. we are looking for a (without telescope) observable solar eclipse
at 15 days distance from an observable lunar eclipse, presumably in Rome or
Campania.
For observation 2. we are looking for a solar eclipse occurring 12 years before
observation 1. at April 30 (or new moon in May) and observable in Campania in the
afternoon and in Armenia somewhat before sunset.
The commonly agreed to datings and corresponding eclipses can be verified with the
NASA Eclipse Web Site (ref.6):
Figure 4: The commonly agreed to solar eclipse corresponding to observation 1. above. The solar
eclipse with its magnitude of 80% is indeed observable in Rome or Campania.

Astronomical dating of Roman time, draft, 2016-02-27, Page 25 of 49
Figure 5: The commonly agreed to lunar eclipse corresponding to observation 1. above. This lunar
eclipse is only partial. The moon just touches into the dark shadow of the earth. The eclipse is 16 days
away from the solar eclipse and not 15 days as specified in Pliny's observation.
Note: Ref.8, p.260: "quindecim diebus" (fifteen days). In French, two weeks are normally said to be
fifteen days. So we might question the precision of an observation saying 15 days. However, we also
might wonder if 16 days is the same as 15 days. What Pliny probably meant is a fortnight, i.e. the
mean time between full moon and new moon which is 14.8 days on average.

Astronomical dating of Roman time, draft, 2016-02-27, Page 26 of 49
Figure 6: The commonly agreed to solar eclipse corresponding to observation 2. above.
Looking for alternative datings
With help of the NASA Eclipse Web Site (ref.6) we have created lists of solar eclipses
from Rome and Naples in Italy and from Jerevan in Armenia covering the time 1 to
500.
From the Rome list we have considered all eclipses with a magnitude above 0.5 and
an altitude above 5 degrees at maximum. For each such solar eclipse we have
looked up a corresponding list of lunar eclipses and selected all partial or total with
an umbral magnitude above 0.1 and within an interval of 13 to 16 days before and
after a solar eclipse. There are 38 solar eclipses in that time span which fulfill these
conditions.
For each such a solar/lunar eclipse pair we have looked for a solar eclipse exactly 12
years before visible in both Jerevan and in Naples. There are three solar/lunar
eclipse pairs which also have a solar eclipse 12 years before only in Armenia, and
one that has such an eclipse only in Naples. There are six solar/eclipse pairs that
have a solar eclipse 12 years before in both Armenia and Naples. Four of these are
not at sunset in Armenia!
Remain two possible sets of observations between 1 and 500, of which one is the
commonly agreed to described above.
The other set is: the solar eclipse of 27 September 303 with a lunar eclipse on 12
September with exactly 15 days distance. The corresponding solar eclipse 12 years
before occurred on 15 May 291.

Astronomical dating of Roman time, draft, 2016-02-27, Page 27 of 49
Note: This selection of data was done with a small computer program especially written for this
operation. The advantage of doing this extraction of data with a computer program is that the risk of
making an error through an oversight is minimized provided that the program has been verified for
correctness. (Actually the result was found "by hand" but was then verified with the program.)
Figure 7: A solar eclipse 232 years later than that commonly agreed to corresponding to observation
1. of Pliny.

Astronomical dating of Roman time, draft, 2016-02-27, Page 28 of 49
Figure 8: A lunar eclipse 232 years later than that commonly agreed to corresponding to observation
1. of Pliny. The lunar eclipse is actually total as seen with a naked eye.
Figure 9: A solar eclipse 232 years later than that commonly agreed to corresponding to observation
2. of Pliny.

Astronomical dating of Roman time, draft, 2016-02-27, Page 29 of 49
Appendix B: Astronomical details about the Gaugamela lunar eclipse
candidates
Several Greek and Roman writers recorded a lunar eclipse that occurred before the
battle between Alexander the Great's army and Persian forces at Gaugamela near
Arbela (todays Erbil in northern Iraq). Details see ref.5, ch.10.5.
The date of the battle is given by Arrian (Anabasis, II, 7.6) as during the month
Pyanopsion when Aristophanes was archon at Athens. This means early in the
autumn (October) RomBC 331 or 330 in our calendar. Plutarch mentions (Life of
Alexander XXXI) that the eclipse preceded the battle by 11 days.
The Nasa Eclipse Web Site (ref.6) shows that there was a large lunar eclipse visible
at Gaugamela on -330 September 20.
Figure 10: Details about the lunar eclipse of -330 September 20. This would date the battle at
Gaugamela to -330 October 1.

Astronomical dating of Roman time, draft, 2016-02-27, Page 30 of 49
Exactly 232 years later, we find another large lunar eclipse on -98 October 6:
Figure 11: Details about the lunar eclipse of -98 October 6. This would date the battle at Gaugamela
to -98 October 17.
Both eclipses would date the battle to October as Arrian says, and both were visible
in northern Iraq, but at different hours of the night. According to the NASA Eclipse
Web Site the partial eclipse in Arbela began: in -330 at 19:46 when the moon was 19
degrees above the horizon (i.e. in the night's second hour), and in -98 at 00:50 when
the moon was 54 degrees above the horizon (i.e. in the night's seventh hour). So
there is a five hours difference between the timings of the two events, see also the
tables below.
A timing of the lunar eclipse at Arbela and a second place is given by both Pliny
(ref.9, ch.72) and Ptolemy (Geography, I, 4). Both writers lived 400 resp. 500 years
after Alexander. Therefore it is impossible that they made the observations
themselves. However neither writer states the source for his timings and they give
completely different hours of the night for the event. The difference is fully three
hours. Both realize correctly that the eclipse would start about two hours local time
later in Arbela than in the middle of the Mediterranean, because Arbela's position is
about 30 longitudinal degrees farther to the east.
Pliny says that the eclipse was seen at Arbela in the night's second hour, and the
same eclipse was seen in Sicily when the moon was just rising.
According to NASA, the partial eclipse began in Syracuse on Sicily in -330 at 17:46

Astronomical dating of Roman time, draft, 2016-02-27, Page 31 of 49
when the moon was 4 degrees below the horizon (i.e. the moon rose eclipsed), and
in -98 at 22:50 when the moon was 53 degrees above the horizon (i.e. in the night's
fifth hour), see also the tables below.
Ptolemy says that the eclipse was seen at Arbela in the night's fifth hour, and at
Carthage in the night's second hour.
According to NASA, the partial eclipse began in Carthage in -330 at 17:31 when the
moon was 8 degrees below the horizon (i.e. a little before sunset, the moon rose
almost totally eclipsed), and in -98 at 22:35 when the moon was 52 degrees above
the horizon (i.e. in the night's fifth hour), see also the tables below.
Pliny's timing for the lunar eclipse at Arbela is fully compatible with the -330 event
and just incompatible with the -98 event. However, Ptolemy's timing is not compatible
with either of the two events, especially not with the -330 event which was already
over in the night's fifth hour at Arbela. We might wonder how it is possible that Pliny,
who was not an astronomer, could have more exact data than Ptolemy, who was a
professional astronomer and had access to the best data available (in Alexandria).
This is even more strange as Pliny lived about hundred years before Ptolemy.

Astronomical dating of Roman time, draft, 2016-02-27, Page 32 of 49
Timings for the two lunar eclipse candidates given by NASA (partial eclipse begins), Pliny and Ptolemy at different places. Pliny reports almost exact timings
for the begin of the partial eclipse (second contact) in -330. This sounds more like a professional observation (or retrocalculation) than a casual observation.
Note: At full Moon, i.e. when a lunar eclipse is at all possible, the moon rises at sunset and sets at sunrise.
For those who want to look at more details:
Time tables generated by using ref.6, Javascript Lunar Eclipse Explorer, for the appearance of the total lunar eclipses at Arbela,
Syracuse and Carthage.

Astronomical dating of Roman time, draft, 2016-02-27, Page 33 of 49

Astronomical dating of Roman time, draft, 2016-02-27, Page 34 of 49
Appendix C: A Babylonian clay tablet mentioning the battle at Gaugamela?
Two cuneiform tablet pieces (BM 36761 + BM 36390) in the British Museum bear the
official title "Astronomical Diary concerning month VI and VII of the fifth year of Artašata
who is called Darius". The two pieces are from the same tablet, but they do not join. The
references to the king, his regnal year and month are missing but can be deduced from
the astronomical data given on the tablet. Moreover, the tablet is a copy of an older one
which was damaged. We use a recent translation of the tablet by Bert van der Spek and
Irving Finkel (ref.34) for the following discussion.
As the tablet is very incomplete, we have to verify which information actually is extant,
and which information is filled in by the translators. The tablet contains (as a Babylonian
astronomical diary usually does) information about prices for staple goods, weather etc.
besides astronomical data and political events. We are only interested in the latter two
types, and only the significant statements.
Astronomical data
The thirteenth, Moonset to sunrise: 32 minutes ... lunar eclipse, in its totality covered.
40 minutes of the night ... Jupiter set; Saturnus ...
The twenty-first: Equinox. I did not watch.
Night of the twenty-ninth: Solar eclipse which was omitted; (it was expected for) about
the 4th minute of the night after sunset.
At that time, Jupiter was in Scorpius; ...
This information is a fully sufficient description of the total lunar eclipse on -330
September 20. The penumbral eclipse at Arbela started 18:49 local time, which was
about 40 minutes after sunset (18:05). At that time Jupiter, which was in Scorpius, set.
All this can be simulated with a modern planetarium software like Stellarium (ref.35). We
can also see that Saturn was in the vicinity of the moon.
Moreover, if the 13th day in that month was September 20, the 21th day would have
been September 28. In the (Julian) year -330 the autumnal equinox would have fallen
on this date. And there was indeed a solar eclipse on -330 October 6, but that one was
visible in Greenland and North America only.
On the other hand, the eclipse described on the clay tablet has nothing to do with the
total lunar eclipse of -98 October 6. At that time Jupiter was in Cancer, and the
autumnal equinox had been passed ten days ago. Though there was a solar eclipse on
-98 October 20 which was visible in Antarctica.
Political events
The twenty-fourth, in the morning, the king of the world ... standard ... Opposite each
other they fought and a heavy defeat of the troops ... The king, his troops deserted him
and to their cities ... land of the Gutians they fled.
That (next) month, from the first until ... came to Babylon, saying as follows: 'Esagila ...
and the Babylonians ... to the treasury of Esagila ...
On the eleventh, in Sippar an order of Al... 'Into your houses I shall not enter.' On the
thirteenth day ... la gate, the Outer gate of Esagila and ...
The fourteenth day, these Greeks a bull ... short ... fatty tissues ... Alexander, the king
of the world, entered Babylon ... horses and equipment ... and the Babylonians and the
people ... a parchment letter to ...
To summarize the tablet: There was a battle 11 days after the lunar eclipse on -330
September 20. About three weeks after that battle the victorious "Alexander, king of the
world" entered Babylon. It is most likely that the battle at Gaugamela is described in
astronomical diary BM 36761 + BM 36390, and that this battle is dated by the tablet to
-330 October 1 as conventionally assumed.

Astronomical dating of Roman time, draft, 2016-02-27, Page 35 of 49
Appendix D: A solar eclipse observation mentioned by Plutarch
This is the report of an eclipse of the sun from Plutarch's dialogue "On the Face in
the Moon" (ref.19, chapter 19):
Now, grant me that nothing that happens to the sun is so like its setting as a
solar eclipse. You will if you call to mind this conjunction recently which,
beginning just after noonday, made many stars shine out from many parts of
the sky and tempered the air in the manner of twilight. If you do not recall it ...
There is no information neither where this eclipse was observed, nor when it was
observed. But the above statement is made by a Lucius who most probably lives in
Rome. Moreover, the appeal to remember is addressed to all participants of the
dialogue, who apparently are from different places in the Roman Empire such as
Italy, Greece and Egypt.
If we do not reject the report as a product of Plutarch's imagination as Robert Newton
(ref.20) does, we should look for an - at least - annular solar eclipse with a maximum
at noon over at least one of the urban centers of the antique world during the adult
lifetime of Plutarch.
Stephenson and Fatoohi (ref.21) consider four possibly total solar eclipses in the
central or eastern Mediterranean during the assumed lifetime of Plutarch (RomAD 45
to 120), and argue that the observation should be connected with the solar eclipse of
71 March 20 over Greece:
Figure 12: The commonly agreed to solar eclipse corresponding to the observation of Plutarch.
Visualized using the Nasa Eclipse Web Site.

Astronomical dating of Roman time, draft, 2016-02-27, Page 36 of 49
Because of the 23° east offset from Greenwich, the local time of the maximum of this
eclipse can be calculated to 09:26 + 1:34= 11:00. From the picture we can also see
that the altitude of the sun changed from 37.8° through 47.8° and ended at 50.7°.
The report saying "beginning just after noonday" is then not a very exact description
of the eclipse.
Furthermore, the totality of this eclipse would have been visible only in Athens and
the south-eastern part of Greece, which dramatically limits the number of participants
in the dialogue who could have been eye witnesses and would remember the event.
As a matter of fact, there was no solar eclipse during the whole first century AD which
came even close to totality in Rome or Campania (see the NASA Eclipse Web Site
(ref.6)).
According to our 232 years hypothesis, Plutarch would have lived in the period 277 to
352 and we would expect a major solar eclipse over the Mediterranean within that
period. The annular eclipse of 334 July 17 was an event at noon visible from Rome,
Campania, southern Greece and Alexandria. It is actually a much better match
towards the observation of Plutarch than the one suggested conventionally.
"Everybody" would have seen it, and even though its obscuration was only about
95%, Venus was visible for several minutes in a position close to the eclipsed Sun.
Maybe therefore Lucius called the phenomenon "conjunction" instead of "eclipse",
and talked about "twilight". In Alexandria also Jupiter was visible above the horizon
(view with a planetarium software like Stellarium (ref.35).
Figure 13: Simulation of the solar eclipse of 334 July 17 at maximum eclipse with Venus visible.
Generated with Stellarium (ref.35).

Astronomical dating of Roman time, draft, 2016-02-27, Page 37 of 49
Figure 14: A solar eclipse corresponding to the observation of Plutarch, if his lifetime is redated by
232 years.
We may actually wonder why there are no reports of this eclipse with its "true" date.
The only instance where we have found that this eclipse is mentioned is in the
Mathesis, a book on astrology by Firmicus Maternus (ref.22).

Astronomical dating of Roman time, draft, 2016-02-27, Page 38 of 49
Appendix E: About the offset between astronomical and dendrochronological
error
A remarkable result of our astronomical study is that the postulated astronomical/
historical error (232 years) appears to be offset by 14 years from the
dendrochronological error (218 years) found in a previous study (ref.2). This means
that, if we are right, then all current dendrochronological dates within the Roman time
complex are given 14 years too young. According to our interpretation, the 14 years
offset is caused by an improper synchronization of the Roman dendro complex
towards Roman history.
The story how this fateful synchronization was done is told by Burghart Schmidt as
follows (ref.37, p.150f):
During the 1960's, oak chronologies covering several hundred years from the
Iron Age and in particular the Roman period were established, but it took
several years to link these chronologies to the absolute tree-ring calendar
because the sparse building activity during the 4th century A.D. left behind
very few wooden remains. Furthermore, that period was affected by such an
unfavourable climate that relatively few oaks from the river plains or valley
slopes became imbedded in the gravel formations, so that even the tree
remains that might be found could not be counted on to fill in the gaps in the
chronology. To localise the tree-ring chronology of the Roman period,
archaeologists thought they could use as a fixed reference point the wooden
remains of the first bridge over the Rhine in Cologne, a bridge whose
construction was set at 310 A.D. on the basis of references in ancient texts.
Thus the youngest tree ring from these bridge piles was attributed to the year
310 A.D., and the Roman tree-ring chronology was considered to be 'nearly
exactly dated'. Anomalies existed, however, as was pointed out for example
by BAATZ (1977). Basing his arguments on three objects which were weIl
dated both archaeologically and dendrochronologically, he concluded that the
archaeological-historical datas were set at 30 to 70 years too old in
comparison with the dendrochronological results. In the light of such
observations we were led to study the wooden remains from the Roman
camp at Oberaden and found they could be dated with certainty within the
Roman period tree-ring chronology of the Cologne laboratory, which was
based on the tree-ring curve "Wederath" of HOLLSTEIN (1972). According to
our results, the Roman camp was built around 38 A.D., a date which was,
however, totally unacceptable to the archaeologists. Numismatical and other
archaeological evidence places the occupation of this Roman camp in the
period from 12 to 9 or 8 B.C. Accordingly we proposed shifting the previously
used Roman period chronology from 38 B.C. to 11 + 5 B.C., that is, by 27 + 5
years towards the present (SCHMIDT, SCHWABEDISSEN 1978). In the
meantime HOLLSTEIN had analysed further finds of wood and had filled in
the last remaining gaps in his chronology. In doing so he confirmed the
correction factor of 27 years (HOLLSTEIN 1977, 1979). One year later
HOLLSTEIN (1980) presented a complete treering calendar extending from
724 B.C. which did not rely on any archaeologically based consideration.
Ernst Hollstein (ref.4, p.10) tells a similar story in German (though with a correction
by 26 years). However, we have found no significant and trustable
dendrochronological bridge between Roman time and early medieval time in
Hollstein's published data (ref.2). Therefore the claim that Hollstein's tree-ring

Astronomical dating of Roman time, draft, 2016-02-27, Page 39 of 49
calendar is free from archaeologically based considerations is plainly invalid.
Moreover, the Oberaden raw data is still unpublished.
The almost incredible fact is that, though since 1984 (ref.38) all long European oak
chronologies are synchronized exactly to the year, no significant bridge between
Roman time and early medieval time has ever been published with raw measurement
data for any of them. However, all dendro labs claim that they worked independently
of each other and of historical considerations.
Hollstein himself noted that there is something wrong with the final "calibration" of the
Roman dendro complex, and he asked for an acceptable interpretation. First he
complained about the above mentioned bridge over the Rhine in Cologne which with
the final calibration of the Roman complex got the building date 336, though it is
mentioned in a panegyric for Constantine the Great already in RomAD 310.
Hollstein also complained about the bridge over the Moselle in Trier which got a safe
dendrochronological felling year of 71 within the Roman complex for one of the large
foundation pillars (though the "uncorrected" year 45 is still commonly seen e.g. on the
Internet). However, that bridge played a role already during the Batavian uprise
RomAD 70 as narrated by Tacitus (ref.39) and the bridge was therefore certainly
completed before that year.
The centre of their line was assigned to the Ubii and Lingones; on the right
wing were the Batavian cohorts, on the left the Bructeri and the Tencteri.
These rushed forward, some by the hills, others between the road and the
Moselle, so rapidly that Cerialis was in his chamber and bed — for he had
not passed the night in camp — when at the same moment he received the
report that his troops were engaged and were being beaten. He kept on
abusing the messengers for their alarm until the whole disaster was before
his eyes: the enemy had broken into the legions' camp, had routed the
cavalry, and had occupied the middle of the bridge over the Moselle,
which connects the remoter quarters with the colony. Undismayed in this
crisis, Cerialis stopped the fugitives with his own hand, and, although quite
unprotected, exposed himself to the enemy's fire; then by his good fortune
and rash courage, aided by the bravest of his troops who rushed to his
assistance, he recovered the bridge and held it with a picked force.
With our dendrochronological offset of 14 years the felling year for the large
foundation pillar becomes RomAD 57. This is 13 years before the fight on the
Moselle bridge during the Batavian uprise in RomAD 70. Indeed a nice, simple and
acceptable interpretation.
The calculation for the Rhine bridge is not that easy as we suspect a
dendrochronological error in the tree-ring sequence.

Astronomical dating of Roman time, draft, 2016-02-27, Page 40 of 49
English Heritage (ref.40, p.16f) reports a similar case:
Annetwell Street, Carlisle. Dating in the historic period can be illustrated by
the results from the complex urban site of Annetwell Street in Carlisle.
Excavations at Carlisle have revealed the remains of many Roman military
and civic structures. Dendrochronology has been important in providing a
detailed independent chronological framework for the development of this
town on the north-west frontier of the Roman Empire in the first century AD.
Before the study, dating evidence relied on coins, pottery, and the writings of
Tacitus, in particular his work on the life of his father-in-law Agricola.These
had been interpreted to indicate that the first fort was constructed in AD 79
(Caruana 1990; McCarthy et al 1989).
Over 500 oak samples were examined from the Annetwell Street excavations
by Cathy Groves (forthcoming (b)).There were numerous samples with more
than 200 rings and these provided a basic chronology for the site. Many of
the other samples were small, no more than 50 – 100mm across, but they
were narrow ringed and often had bark edge thus providing precise
dates.The analysis indicated that the timbers were local; they seem to have
been used soon after felling although reuse of timber was sometimes
detected. The first wooden fort was constructed from timbers felled in the
winter/early spring of AD 72/73. Modifications were made to the fort
throughout the period AD 72 – 82, and there was a major rebuild of the
interior in AD 83 – 5.There was no detectable felling of timber during AD 86 –
92, a period which coincides with a major reorganisation of forces within the
Roman Empire. More timbers were felled in AD 93/94 with a few felled during
AD 95 – 7. The surrounding rampart shows a similar development to that of
the fort. It was constructed in AD 72/73, repaired in AD 84/85, and finally
rebuilt in AD 93/94. After this, stone replaced timber as a building material
and dendrochronology ceases to be useful.
The results outlined above are likely to change the historical interpretation of
the development of the Roman northwest frontier in Britain during the first
century AD. They also confirm that the writings of Tacitus are not always
reliable. His date of AD 79 for the founding of Carlisle coincides with the time
when his father-in-law Agricola was governor of Britain whereas it is now
clear from dendrochronology that Carlisle was in fact founded under Petillius
Cerialis some six or seven years earlier. It has long been suspected that
Tacitus was economical with the truth so as to improve the image of Agricola
(Birley 1973; Caruana 1990). Now that this theory has been confirmed by
dendrochronology, the use of the term ‘Agricolan’ in British history and
archaeology will have to be revised.
With our dendrochronological offset of 14 years the rampart was constructed in
RomAD 58/59, repaired in RomAD 70/71, and finally rebuilt in RomAD 79/80.
Tacitus' date of RomAD 79 for the founding of Carlisle coincides certainly not with
the initial foundation of the fort, but well with the major late rebuilding phase. See the
following table as our contribution to reestablish the trustworthiness of Tacitus'
chronological statements:

Astronomical dating of Roman time, draft, 2016-02-27, Page 41 of 49
Year
RomAD
Roman
Emperors
Governors of
Britain Carlisle dendro
(ref.41)
corr. by 14 years
Agricola's life (ref.42) History of Britain
(ref.43)
57 Nero Quintus Veranius problems in
northern Britain
(Brigantia);
Venutius' first
rebellion
58 Gaius Suetonius
Paullinus 1st timber fort,
construction military tribune in Britain,
Paullinus' adjutant
59
60 further structures
added uprise of the Iceni
and others
(Boudica)
61
62 minor alterations
Publius Petronius
Tur
p
ilianus
63 Marcus Trebellius
Maximus
64 quaestor in Asia
65
66 plebeian tribune
67
68 praetor
Galba
69 Otho major rebuild of
interior Venutius' second
rebellion
Vitellius Marcus Vettius
Bolanus
70 Vespasian commander in Britain
(Legio XX Valeria Victrix)
71
Quintus Petilius
Cerialis
72
73
74 governor of Gallia
Aquitania
Sextus Julius
Frontinus
75
76
77 consulship; arrives as governor in Britain late
in the season, attack on An
g
lese
y
Gnaeus Julius
Agricola
78 building of forts and garrisons
79 2nd timber fort,
construction Roman army advances into Scotland; building
of forts
Titus
80
81 further structures
added
Domitian
82
83 battle of Mons Graupius, official circum-
navigation of Britain

Astronomical dating of Roman time, draft, 2016-02-27, Page 42 of 49
According to our interpretation, the second timber fort is the one built by Agricola in
RomAD 79 exactly as stated by Tacitus. However, the erection of the first timber fort
seems to be related to upheaval in Brigantia in northern Britain. A fort in Carlisle
allowed the Romans to be in place and control what was going on. Also the major
rebuild of the interior of the fort in RomAD 69/70 appears to be related to trouble in
Brigantia.
As we have three distinct dendrochronological dates in Carlisle within a time range of
21 years, we can use these dates to validate our postulated synchronization error
between dendrochronological and historical dating of Roman time. When the 14
years offset is corrected, the archaeological results now comply with the historical
timings. This further strengthens our hypothesis from which we originally derived the
size of the offset.

Astronomical dating of Roman time, draft, 2016-02-27, Page 43 of 49
Appendix F: The Gregorian calendar reform
The Julian calendar, introduced by Julius Caesar in RomBC 46, was a reform of the
ancient Roman calendar which had got out of hands as the calendar had drifted out
of alignment with the tropical year so that e.g. harvest festivals no longer fell at
harvest time. The Julian reform took effect in RomBC 45 and was the predominant
calendar in most of Europe and in European settlements in the Americas and
elsewhere, until it was refined and superseded by the Gregorian calendar.
The Julian calendar has a regular year of 365 days divided into 12 months. A leap
day is added to February every four years. The Julian year is, therefore, on average
365.25 days long. It was intended to approximate the tropical (solar) year. Although
Greek astronomers had known, at least since Hipparchus, that the tropical year was
a few minutes shorter than 365.25 days, the calendar did not compensate for that
difference. As a result, the calendar year gained about three days every four
centuries (or more exactly 1 day per 128.2 years) compared to observed equinox
times and the seasons. When this discrepancy became obvious it was corrected by
the Gregorian calendar reform of 1582. The Gregorian calendar has the same
months and month lengths as the Julian calendar, but inserts leap days according to
a different rule.
By 1582, the vernal equinox had moved backward in the calendar so that it occurred
astronomically about March 11, i.e. 10 days earlier than March 21 which was the
nominal (given) date used as the benchmark for the calculation when the Christian
feast of Easter should be celebrated. Referring to the first council of Nicaea in 325,
Pope Gregory XIII wrote in his papal bull "Inter Gravissimas":
So thus that the vernal equinox, which was fixed by the fathers of the [first]
Nicene Council at XII calends April [March 21], is replaced on this date, we
prescribe and order that there is removed, from October of the year 1582, the
ten days which go from the third before Nones [the 5th] through the day
before the Ides [the 14th] inclusively.
The removal of 10 days from the calendar in October 1582 compensated for the drift
during 1282 years (10 x 128.2) between the astronomical date for the vernal equinox
and its nominal date (March 21). The expected number of years between 1582 and
the council of Nicaea in 325 is almost the same (1257 years, though the correction
could only be done with full days). Therefore we would presuppose that March 21
was both the nominal date and the astronomical date for the vernal equinox in both
325 and after 1582.
We know that this statement was true after 1582 (as this was the intention of the
calendar reform), but was it true in 325? The nominal difference between 1582 and
325 is indeed 1257 years, though if we have invented (phantom) years within that
period then our calculations above are misleading (and actually based on some sort
of circular reasoning). Are there any observations of the vernal equinox around the
Nicaea council or before? For this we have to rely on the oldest texts available which
acknowledge the Julian calendar.

Astronomical dating of Roman time, draft, 2016-02-27, Page 44 of 49
Anatolius of Alexandria (dead 283) relates in his Paschal Canon (ref.44) to the Julian
calendar and says:
... with respect to the day of Easter, that attention must be given not only to
the course of the moon and the transit of the equinox, but also to the
passage (transcensum) of the sun ...
There is, then, in the first year, the new moon of the first month, which is the
beginning of every cycle of nineteen years, on the six and twentieth day of
the month called by the Egyptians Phamenoth. But, according to the months
of the Macedonians, it is on the two-and-twentieth day of Dystrus. And, as
the Romans would say, it is on the eleventh day before the Kalends of
April. Now the sun is found on the said six-and-twentieth day of
Phamenoth, not only as having mounted to the first segment, but as
already passing the fourth day in it. And this segment they are
accustomed to call the first dodecatemorion (twelfth part), and the equinox,
and the beginning of months, and the head of the cycle, and the starting-
point of the course of the planets. And the segment before this they call the
last of the months, and the twelfth segment, and the last dodecatemorion,
and the end of the circuit of the planets. And for this reason, also, we
maintain that those who place the first month in it, and who determine the
fourteenth day of the Paschal season by it, make no trivial or common
blunder.
Alden Mosshammer's (ref.29) and our interpretation of what Anatolius says is that
Easter may not be celebrated before the vernal equinox has passed, and that the
nominal day for the vernal equinox is March 22. And that at this date the sun already
has passed the equinox astronomically with four days, meaning that the
astronomical equinox was on March 19 in the late 3rd century AD.
This interpretation of Anatolius' statements presupposes that somebody living near
his time, or he himself, has determined the date for the vernal equinox
experimentally. This is not at all impossible, as Anatolius had been a scholar in
Alexandria and had expert knowledge in astronomy (ref.29, p.130):
Eusebius says that Anatolius was an Alexandrian by birth and one of the
most eminent scholars of the time. He excelled in mathematics, astronomy,
physical science, philosophy, and rhetoric. At the invitation of his fellow
citizens, he founded a school of Aristotelian philosophy at Alexandria.
If the vernal equinox was astronomically on March 19 in the late 3rd century AD, it
was on March 21 or 22 when the Julian calendar was introduced about 300 years
before. Several scientists have noted the brisance of this fact and concluded
accordingly that Anatolius must have erred. There is also a latin version of Anatolius'
Paschal Canon, mentioning March 25 instead of March 22 for the vernal equinox.
This version is regarded as a 7th century forgery. Read the complete discussion in
ref.29, ch.8.
If we assume that Anatolius has not erred, the vernal equinox was astronomically on
March 19 also at the Nicaea Council in 325, only a few years after Anatolius' death.

Astronomical dating of Roman time, draft, 2016-02-27, Page 45 of 49
As the vernal equinox was astronomically on March 11 in 1582, there are only eight
days offset between the two observations. This equals 1026 years if we multiply 8
with 128.2 which is the number of years per one day offset (see above).
However, the nominal difference between the date for the Gregorian reform and
Nicaea is instead 1257 years (see above). This means that the historical time line
between 325 and 1582 counts 231 "phantom" years too much.
Note: The calculation of the size of the calendar error is only a very rough estimation
as the offset increases with one day every 128 years. So the close compliance of the
231 phantom years with our 232 postulated years is only a chimera.

Astronomical dating of Roman time, draft, 2016-02-27, Page 46 of 49
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