The Thule (USˈθuːli, ˈtuːli, UKˈθjuːli) or proto-Inuit were the ancestors of all modern Inuit. They developed in coastal Alaska by the year 1000 and expanded eastward across northern Canada, reaching Greenland by the 13th century. In the process, they replaced people of the earlier Dorset culture that had previously inhabited the region. The appellation "Thule" originates from the location of Thule (relocated and renamed Qaanaaq in 1953) in northwest Greenland, facing Canada, where the archaeological remains of the people were first found at Comer's Midden. The links between the Thule and the Inuit are biological, cultural, and linguistic. Evidence supports the idea that the Thule (and also the Dorset, but to a lesser degree) were in contact with the Vikings, who had reached the shores of Canada in the 11th century as part of Norse colonization of North America. In Viking sources, these peoples are called the Skrælingjar. Some Thule migrated southward, in the "Second Expansion" or "Second Phase". By the 13th or 14th century, the Thule had occupied an area inhabited until then by the Central Inuit, and by the 15th century, the Thule replaced the Dorset. Intensified contacts with Europeans began in the 18th century. Compounded by the already disruptive effects of the "Little Ice Age" (1650–1850), the Thule communities broke apart, and the people were henceforward known as the Eskimo, and later, Inuit. The Thule Tradition lasted from about 200 BC to 1600 AD around the Bering Strait, the Thule people being the prehistoric ancestors of the Inuit. Thule culture was mapped out by Therkel Mathiassen, following his participation as an archaeologist and cartographer of the Fifth Danish Expedition to Arctic America in 1921–1924. He excavated sites on Baffin Island and the northwestern Hudson Bay region, which he considered to be the remains of a highly developed Eskimo whaling culture that had originated in Alaska and moved to Arctic Canada approximately 1000 years ago.