Prior to the Viking colonisation, in the 10th Century, Greenland had been inhabited only by the nomadic peoples of the polar ice-fields, who appear (so far as can be told, given the limited archaeological and societal evidence now available) to have abandonded any permanent degree of settlement by the time the first Vikings arrived.
The Vikings (probably originating in Iceland) arrived in Greenland in the 980sCE. They settled on the south-western coasts and gave the settlement its name either because, at this point in history, during the spring, the land did support foliage, or as an early advertising gimmick, to get more settlers. Eric the Red is supposed to have spent 3 years exploring the coastline (during a period of exile from Iceland) and to have encouraged 25 ship-loads of settlers to cross the intervening seas. 14 ships are said to have arrived safely.
The settlment coalesced around two sites, the Western and the Eastern, and may, at its height, have numbered between 3000 and 5000 souls. The settlers traded in walrus ivory, and exported seals, rope and cattle hides, in return for European iron and timber.
Greenland did not flourish as a going concern: probably due to adverse climatic changes. The Western (smaller) settlement is known to have been abandoned around 1350; by 1378 there was no longer a bishop, and the last record is of a wedding in 1408.
There is also evidence that, by this stage, Arctic cultures had moved back into first the northern landmass and then further south, working and hunting along the coastlines. Members of these groups had an inherent advantage over the settlers, in that they were acclimatised and accustomed to the conditions, and had, over centuries, evolved coping strategies beyond the scope of incomers. There remain some accounts of trade between the two groups, but also of violence and conflict between them. The Viking settlements died out; the Arctic peoples survived.
Although Denmark and Norway (for a time a merged kingdom) continued to claim overlordship over the settlement areas, no further attempt at permanent settlement was made during period and Greenland passed, to a great extent, into legend and myth.