became Canada. Oleson published Early Voyages and Northern Approaches in 1963. The book covered two different aspects of the early European explorations: the westward expansion of the Norse, to Iceland, Greenland and the northern portions of Canada, and later European explorations in the Arctic, primarily by English explorers searching for the North-West Passage to Asia. His primary thesis in relation to the early Norse explorations was that the Thule culture of the High Arctic was the result of inter-marriage and cultural fusions between the Norse settlers of Greenland, moving west into the Arctic, and the pre-existing Dorset culture. In support of this thesis, Oleson relied on his interpretation of archaeological evidence, such as the structure of stone shelters in the eastern Arctic which he saw as similar to Icelandic structures; the development of a sea-culture including whaling from small boats, which he saw as similar to Norse practices, and a body of academic historical research from Icelandic scholars, which was not generally available to Canadian researchers. He also relied on the Norse sagas, which have several descriptions of encounters between Norse and indigenous peoples of the Arctic. Oleson's thesis also helped to explain the gradual disappearance of the Norse settlements in Greenland. In his view, they did not simply disappear; rather, the Norse gradually fused with the Dorset peoples of the High Arctic. Academic response Oleson's thesis was controversial and attracted considerable opposition and critical reviews, particularly from practitioners of Arctic archaeology. The prevailing interpretation was that the Thule culture had its origins in Alaska and had moved eastward. Oleson's thesis was that the Thule originated in the eastern Arctic and gradually moved westward. Several reviewers challenged Oleson's interpretation, particularly William Taylor, who was one of the leading experts in Arctic archaeology at the National Museum of Canada, as well as Wilcomb E. Washburn from the Smithsonian Institution. The one contemporary review which was more favourable was from Thomas E. Lee, another archaeologist from the National Museum of Canada, who wrote that he had read Oleson's "tremendous work" six times, cover to cover, and thought it was "...by far the most important and instructive single work to come out of Arctic research in this field in recent times." The general editors of the Centenary Series were somewhat taken aback by the criticism and sometimes hostile reaction to Oleson's book, but were hampered in their ability to respond by his death.