The Thule culture — the immediate ancestors of modern Iñupiat — emerged around 1,000 CE and spread rapidly across Arctic Alaska and Canada, eventually reaching Greenland, where their descendants became the Inuit peoples of the eastern Arctic.

What drove the Thule expansion was technology: specifically, the development of efficient whaling technology — the umiak, the toggling harpoon, the bladder float — that allowed coastal Arctic peoples to take bowhead whales.

Bowhead whales are among the largest animals on Earth, averaging 50 to 80 feet in length and 75,000 to 200,000 pounds in weight.

A single successfully harvested bowhead could provide food for an entire community for months — the caloric and nutritional density of whale meat and muktuk made the bowhead the keystone resource of Arctic coastal life.

Hunting bowhead whales in the Arctic Ocean required everything the Iñupiat had developed: the umiak to approach the whale silently in ice-choked waters, the toggling harpoon that held fast once embedded, the bladder floats that prevented the struck whale from diving and exhausting itself, the physical courage and coordination of a whaling crew, and the deep knowledge of whale behavior and movement patterns that made the hunt possible.