Spread of the Thule Inuit
Stage I
The weather improved in the 11th century, with fewer icepacks which has made hunting difficult.
Stage II
Whalers and hunters had longer seasons for their work.
Stage III
They became better hunters and had better equipment than the other people in the Arctic.
Stage IV
They spread across the Arctic to Greenland. It took about 200 years for the Inuit to replace the other Arctic people.
Stage V
They continued to spread south as far as Hudson Bay and the Ungava Peninsula.
James Green: Native peoples of the Americas; Oxford University Press, 1993, page 11