Greenland was discovered and settled by Nordic Europeans in the 10th Century CE. The first settlers left Iceland in a fleet of 25 ships, of which only 14 ships arrived at Greenland in the summer of 985 CE. Other settlers soon followed and Greenland was a going concern. There were two separate colonies; the larger Eastern Settlement and the smaller Western Settlement. The settlements grew up around navigable fjords, fresh water lakes and rich pasture lands. The Greenlanders established farms and raised cattle, sheep and goats. Both settlements traded narwhal tusk and walrus ivory, polar bear furs, seal and cattle hides and hunting falcons for iron tools, wood and supplemental food items, such as raisins and wines.
Archeological digs around the main population centers showed that the people were generally in good health, but violence seemed to be an issue; with one body found with a knife in its ribs and 13 males bodies ranging in age from teen to middle aged also showing signs of violence. At the peak of the colony, there were between 400 and 500 farms with a total population of about 5000 people. The settlement was also made a church diocese with a bishop appointed to oversee the church’s affairs at the edge of the known world.
After about 300 years of relatively good living, things started to go badly for the Greenlanders. First, the Western Settlement was abandoned sometime before 1350 CE. Then trade dropped off to nothing. In 1408 the Greenlanders record a wedding; this is the last written record of any event in Greenland. In 1540 a boat from Iceland was blown off course and made landfall on Greenland, they find no one living, but do find a single dead man on the shore. Sometime between 1408 and 1540 the colony was abandon or died out.
Theories as to what did in the Greenland Norse abound. Jared Diamond has summarized that one or any combination of five different factors were responsible: environmental damage caused by over farming, climate change or global cooling, as the Earth entered the Little Ice Age , war with the hostile Inuit, loss of trade with Europe, and failure to adapt to new conditions.
None of these tell us what happened to the Norse people themselves. Again theories abound; did the population merely die off, where they wiped out by a plague, did the Inuit kill them, did they assimilate or interbreed with the Inuit, or did some leave and others stay behind and die. The current evidence does not show any mass die off such as from a plague nor that the Inuit slaughtered the Norse, even though there does seem to have been some hostilities with the Inuit. There is no genetic evidence of interbreeding between the Norse and the Inuit. Given what we know the best theory based on the evidence is that those wanting to and able to simply left Greenland, most likely leaving on the occasional ship that would land and returning to Europe. Those that did not want to leave or could not do so, stayed and died.
Jared Diamond, Collapse: How Societies Choose to Fail or Succeed( New York: Viking Press 2004).