One of the strangest and least known chapters in North American history is surely the story of Greenland’s Norse (Vikings) and the Thule people (Inuit).

The standard narrative of North American history is turned on its head here, where centuries ago a Native American group displaced then colonized land inhabited by the Vikings.

Indeed, many of us don't know that Greenland is part of North America. Yet it's connected to Canada by a underwater ridge less than 180 metres deep, and at its nearest point, is only 26 kilometres from Ellesmere Island.

In 982 AD Vikings arrived in southern Greenland from nearby Iceland. They found a land that was uninhabited and soon established several settlements. Over the next few centuries the Viking settlements flourished and Greenland became medieval Europe’s "farthest frontier."

Though the first Vikings to arrive in Greenland followed traditional pagan beliefs, Christianity arrived there shortly after and churches and even a cathedral were built on the island.

The Catholic Church appointed a bishop for Greenland and as the Vikings gave up their old ways, they also lost much of their fierce reputation as warriors and raiders. Archaeologists estimate that at their height, the Norse numbered up to 5,000, perhaps even 6,000 in Greenland. (A very large amount given how small the world’s population was in the Middle Ages.) Some of the Vikings even ventured over to North America, visiting what is now northeastern Canada and establishing a settlement at L’Anse Aux Meadows, Newfoundland.

And they also travelled hundreds of kilometres north of their own settlements in Greenland to summer hunting grounds, where they killed polar bears, narwhals, and seals, trading the pelts and ivory with Europe. But a happy end for the Greenlanders wasn't meant to be.

In distant Alaska, a new culture was rising — the Thule (ancestors of today’s Inuit). The Thule, originally from Siberia, were gradually expanding across the Arctic, displacing the older, aboriginal Dorset people.

By roughly 1200 AD, the Dorset had vanished, killed off in warfare with the Thule or unable to survive the hardship occasioned by competition for resources with the invaders. (Inuit oral traditions tell of how the Dorset were a gentle people without bows and arrows, and thus easy to kill and drive away.) The Thule continued their expansion across the Canadian Arctic and sometime between 1100 AD and 1300 AD, spread into northern Greenland (at least more than a century after the Vikings had settled there). The Thule then moved south along the coast, eventually coming into contact with the Norse settlements. The surviving written records from the Norse tell of attacks by the invaders. Some of the sources even say the Thule newcomers massacred a whole Norse settlement.

Faced with a changing climate (the world was then cooling during the little Ice Age), hostile invaders, and perhaps internal problems, the Norse society in Greenland collapsed.

By sometime in the 15th century, Greenland’s Norse seem to have disappeared entirely, their territory eventually overrun and colonized by the Inuit, and their story largely forgotten by the modern world.