Biologically, culturally and linguistically the Inuvialuit are Inuit, closely related to all other Inuit people living across the top of the North American continent from Bering Strait to east Greenland. All share a recent common origin in a culture which archaeologists call "Thule" which arose in northwestern Alaska about 1100 years ago. Over the course of the next few centuries, Thule pioneers spread rapidly east throughout the Arctic in a series of migrations which changed the ethnic map of the entire North American Arctic. The earliest well-attested Thule site in Canada is located on southern Banks Island, and dates to about the year A.D. 1000. Within less than two centuries Thule hunters had spread as far as northern Greenland.
They were not entering an unoccupied land. Most of Arctic Canada and Greenland was the home of an eastern "Palaeoeskimo" people known to archaeologists as Dorset. Within a few decades, or at most a few centuries, they disappeared entirely,apparently pushed into oblivion by the more vigorous and more accomplished newcomers. Dorset culture, however, is known only as far west as Dolphin and Union Strait and the western coast of Victoria Island. No archaeological sites dating to the immediate pre-Thule period are known from the western part of the Canadian Arctic, so we have no clear idea who (if anyone) the first Thule immigrants met there.
These first Thule ancestors of the Inuvialuit are themselves known more by conjecture than direct evidence, in large part because land subsidence seems to have destroyed almost all of the relevant archaeological sites. Of over three hundred sites documented between the Alaskan border and Franklin Bay, only two clearly date to the Thule period. Fortunately, Thule culture is very well known from most other areas of the Arctic, so that certain general statements can be made about local Thule culture despite the dearth of local information.