Introduction (by Diego Escolar, Corpus Director) During the last 25 years, ethnohistory, the historical anthropology or, plainly, the history of indigenous societies from Patagonia, Pampean area and Araucanía have experienced a remarkable development. This is especially conspicuous as regards the relationship between those indigenous groups and the Creole society during the Nation-State formation process in the 19th century, being now this relationship a major concern to the majority of studies on those groups and others with different regional context, in Argentina as well as in Chile. Martha Bechis’s PhD Dissertation, that we present here, can be considered, if not a cornerstone, the main influence—the “original accumulation” of intellectual resources, the working hypothesis, the emphasis on the reconstruction of processes rather than the definition of “cultural areas”, the linking of wide and scattered documentary corpus—to this strong current of study and the problems it deals with. The thesis was defended in the New School for Social Research in 1984, and the jury was formed by Stanley Diamond, Rayna Rapp and William Roseberry. It tackled the “diachronic of ethnicity” of the various communities globally named as Araucanos in the context of the Argentinean and Chilean nations-states formation. The principal thesis was that the loss of independence and sovereignty by the Araucanos and their inclusion in the national states as “ethnic groups” was due not to the military superiority of the Creole, but to the political and economical processes that led to the building of territory, population, and market entailed in the formation of modern national states. Bechis points out that it is only during the decade of 1870 when the indigenous chieftains first feel that they may lose sovereignty and the Creole that they may jeopardize it. The speed with which these feelings politically materialized, in only ten years, as the rupture of a long statu quo between both societies and the death of the indigenous sovereignty is a function, says Bechis, of the incorporation of the Creole societies into the financial capitalism and, at the same time, an unprecedented increase of the indigenous societies’ wealth and strength to the end of their sovereignty process. A large part of these theories, the corpus used by Bechis, her rigorous analyses and incisive questions can be traced through her later production up to the present, though her authorship or inspiration is not always acknowledged as it should. This might be due in fact to the absence of edition of her thesis. For some reason we do not understand, her Dissertation has never been published as a book, though it has circulated in an almost clandestine way, distributed most of the times by Martha herself, thus resembling the stories of the lost archives of indigenous history—like the one that tells how Calfuncurá was buried in the Pampean sands so that his body would not be appropriated by the Argentinean army—that Martha used to tell us, ecstatic participants of her PhD seminar, “Ethnohistory as historical dynamics of hegemonic situations among alternate groups”, held in 1999 at the Philosophy and Literature School in the Buenos Aires University. Together with those stories, Martha used to give us solitary paper boats, photocopies of fragments of her thesis, of which she had a single typed copy. With this text, the author founded a new field and at the same time acted as a hinge between historiographical and social-anthropological studies of the “pan-araucana area”, while setting a path with her seminars and photocopies. She left important teachings that too often have been forgotten in spite of their importance. She proved, in an early stage, the potential of connecting anthropological and historiographical perspectives, and that it is no longer possible to think of “indigenous societies” as political bodies separated from “Creole societies”, or Argentinean and Chilean national histories without taking into consideration at the same time the parallel dynamics of indigenous histories of the “pan-araucana” area (the word “araucana” itself would show the border condition between the classic and the newer studies, enabling a whole new horizon or problems that could not be thought of back then). With the launching of this new Dissertations section in CORPUS, we wanted to pay homage to Martha Bechis and her PhD Dissertation, which we offer for the first time for the public in its original format, thus perpetuating her legend. We sincerely thank Martha for entrusting this material to us, thus widening the scope of Corpus by unclassifying this true jewel. We aspire to continue presenting unpublished classic works, but also to offer this space to quality productions, i.e. PhD, Master and degree dissertations, welcoming those works that publishing companies reject for marketing reasons but which have an eager reading public.