Warfare was common among Inuit groups with sufficient population density. Inuit, such as the Nunatamiut (Uummarmiut) who inhabited the Mackenzie River delta area, often engaged in common warfare. The Central Arctic Inuit lacked the population density to engage in warfare. In the 13th century, the Thule culture began arriving in Greenland from what is now Canada. Norse accounts are scant. Norse-made items from Inuit campsites in Greenland were obtained by either trade or plunder. One account, Ívar Bárðarson, speaks of "small people" with whom the Norsemen fought. 14th-century accounts relate that a western settlement, one of the two Norse settlements, was taken over by the Skræling.