| Overview of the Viking Age genomic dataset. a, Map of the Viking World from eighth to eleventh centuries ad, showing geographical location and broad age category of sites with ancient samples newly reported in this study. Age categories of sites (circles) are coloured-coded as: dark green, LNBA (2400-500 bc); light green, Iron Age (500 bc-ad 700); yellow, Early Viking Age (ad 700-800); Viking Age (ad 800-1100); Medieval and Early Modern (ad 1100-1600). Red region, area of Viking origins; green region, area of Viking raids, settlement and trade; dark blue region, area of pioneer Viking colonization. b, All of the ancient individuals from this study (n = 442), and previously published Viking Age samples from Sigtuna 10 and Iceland 18 , categorized on the basis of their spatiotemporal origin. The ancient samples are divided into the following five broad categories: Bronze Age (BA), Iron Age (IA), Early Viking Age (EVA), Viking Age (VA), Medieval (MED) and Early Modern (EM). Random jitter has been added along the x axis in each category to aid visualization. LNBA, Late Neolithic and Bronze Age; Norse W, Norse western settlement; Norse E, Norse eastern settlement; Norway S, southern Norway; Norway N, northern Norway; Norway M, middle Norway.

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... explore the genomic history of the Viking Age, we shotgunsequenced DNA extracted from 442 human remains from archaeological sites dating from the Bronze Age (about 2400 bc) to the Early Modern period (about ad 1600) (Fig. 1, Extended Data Fig. 1). The data from these ancient individuals were analysed together with published data from 3,855 present-day individuals across two reference panels (Supplementary Note 6), and data from 1,118 ancient individuals (Supplementary Table ...

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... present-day European individuals (n = 1,464) (Supplementary Notes 6, 10, 11). Genetic clustering using multidimensional scaling and uniform manifold approximation and projection (UMAP) shows that Viking Age Scandinavian individuals cluster into three groups by geographical origin, with close affinities to their respective present-day counterparts (Fig. 3a, Supplementary Fig. 10.1). Some individuals-particularly those from the island of Gotland in eastern Sweden-have strong affinities with Eastern Europeans; this probably reflects individuals with Baltic ancestry, as clustering with Bronze Age individuals from the Baltic region is evident in the identity-by-state UMAP analysis (Fig. 2b) and through f 4 ...

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... We find ancestry components in Scandinavia with (inexact and indicative) affinities with present-day populations ( Supplementary Fig. 11.11), which we refer to as 'Danish-like', 'Swedish-like', 'Norwegian-like' and 'North Atlantic-like' (that is, possible individuals from the British Isles entering Scandinavia). The sampling is heavily structured, so these complex results (Supplementary Fig. 11.12) are visualized over time and space (Fig. 4) using spatial interpolation 12 to account for sampling locations and report significant trends (Supplementary Table 11.2) using linear regression (Supplementary Notes 11, 12). ...

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... with (inexact and indicative) affinities with present-day populations ( Supplementary Fig. 11.11), which we refer to as 'Danish-like', 'Swedish-like', 'Norwegian-like' and 'North Atlantic-like' (that is, possible individuals from the British Isles entering Scandinavia). The sampling is heavily structured, so these complex results (Supplementary Fig. 11.12) are visualized over time and space (Fig. 4) using spatial interpolation 12 to account for sampling locations and report significant trends (Supplementary Table 11.2) using linear regression (Supplementary Notes 11, ...

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... and Swedish-like components cluster in Norway and Sweden, respectively, whereas Danish-like and North-Atlantic-like components are widespread (Fig. 4, Supplementary Fig. 11 ...

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... Table 6). Unexpectedly, Viking Age individuals from Jutland (Denmark) lack Swedish-like and Norwegian-like genetic components ( Supplementary Fig. 11.12). We also find that gene flow within Scandinavia was broadly from south to north, dominated by movement from Denmark into Norway and Sweden (Supplementary Table 11.2). ...

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... quantified genetic diversity using two measures: conditional nucleotide diversity (Supplementary Note 9) and variation in inferred ancestry on the basis of ChromoPainter results (Extended Data Fig. 6, Supplementary Note 11, Supplementary Fig. 11.13). We also visualized this diversity as the spread of individuals on a multidimensional scaling plot based on a pairwise identity-by-state sharing matrix (Fig. 3b). ...

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... fine-scale ancestry analyses of genomic data are consistent with patterns documented by historians and archaeologists (Figs. 3, 4, Supplementary Fig. 11.12): eastward movements mainly involved Swedish-like ancestry, whereas individuals with Norwegian-like ancestry travelled to Iceland, Greenland, Ireland and the Isle of Man. ...

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... between Scandinavians (mostly from Norway) and individuals from the British Isles, similar to the first settlers of Iceland 18 . We see no evidence of long-term inbreeding in the genomes of Greenlandic Norse individuals, although we have only one high-coverage genome from the later period of occupation of the island (Supplementary Note 10, Supplementary Figs. 10.2, 10.3). This result could favour a relatively brief depopulation scenario, consistent with previous demographic models 32 and archaeological findings. We also find no evidence of ancestry from other populations (Palaeo-Eskimo, Inuit or Native American) in the Greenlandic Norse genomes (Supplementary Fig. 9.4), which accords with the ...

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... further examined ancient ancestry in present-day populations using fineSTRUCTURE (Supplementary Note 11, Supplementary Fig. 11.14). Within Scandinavia, most present-day populations resemble their Viking Age counterparts. ...

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... small Scandinavian ancestry component is present in Poland (up to 5%). Within the British Isles, it is difficult to assess how much of the Danish-like ancestry is due to pre-existing Anglo-Saxon ancestry, but the Viking Age contribution does not exceed 6% in England (Supplementary Note 11). The genetic effects are stronger in the other direction. ...

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... via identity-by-descent within the context of a reference panel of 1,464 present-day Europeans, using IBDseq 99 (version r1206) with default parameters. We conducted genetic clustering by MDS on a distance matrix obtained from pairwise identity-by-descent sharing and UMAP to reveal fine-scale population structure among Viking Age individuals. Fig. 11.7), and that sequence depth did not significantly affect inferred ancestry ( Supplementary Fig. 11.8) by downsampling individuals with high-depth data available, rephasing, re-imputing and repainting them, and assigning ancestry using the above procedure. Results 2× and above were extremely similar, whereas at 1× there was some loss of ...

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... conducted genetic clustering by MDS on a distance matrix obtained from pairwise identity-by-descent sharing and UMAP to reveal fine-scale population structure among Viking Age individuals. Fig. 11.7), and that sequence depth did not significantly affect inferred ancestry ( Supplementary Fig. 11.8) by downsampling individuals with high-depth data available, rephasing, re-imputing and repainting them, and assigning ancestry using the above procedure. Results 2× and above were extremely similar, whereas at 1× there was some loss of precision but the broad structure remained clear. ...

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... we ran a principal components analysis of the ancient + modern populations painted against our donor populations (Supplementary Fig. 11.9) as well as an all-versus-all ChromoPainter analysis including modern and ancient individuals ( Supplementary Fig. ...

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... we ran a principal components analysis of the ancient + modern populations painted against our donor populations (Supplementary Fig. 11.9) as well as an all-versus-all ChromoPainter analysis including modern and ancient individuals ( Supplementary Fig. 11.10). ...

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... We performed a simulation study to validate this measure (Supplementary Information section 11, Supplementary Fig. 11.13), which allowed us to calibrate the expected diversity as a function of sample size. ...

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... then used neoscan in Ohana 36,103 to scan for variants with allele frequencies that were strongly associated with time, after controlling for genome-wide changes in ancestry that might have also occurred over time. We analysed only sites with a minor allele frequency >1% (Supplementary Note 14). ...