Groups of Eskimos have at various times migrated via the Canadian Arctic islands into Greenland. The Paleo-Eskimo were represented by the Saqqaq culture and the Dorset Culture (c. 3000 B.C. to c. A.D. 900). The Neo-Eskimo, the Thule Eskimo, arrived in Greenland about A.D. 900. They were the first Eskimos encountered by Europeans, Norse settlers from Iceland who lived in Southwest Greenland from about A.D. 982 to 1500. During the sixteenth to nineteenth centuries the West Greenlanders occasionally had contact with European explorers and whalers and some trading took place, but it was the Danish-Norwegian colonization efforts in 1721 that resulted in radical changes of West Greenland culture and society. In the eighteenth century mission and trading stations were established all along the coast. In the eighteenth and nineteenth centuries the population of southern East Greenland settled in southern West Greenland. The Colonial administration was paternalistic and the isolationist policy was not abandoned until after World War II, when modernization of the Greenlandic society accelerated as a result of the state-directed development policy.