As a result of the 1940 Moscow Peace Treaty that concluded the Winter War, Finland ceded the area of Finnish Karelia and other territories to the Soviet Union. As a result, about 410,000 Finnish Karelians, or 12% of Finland's population, were relocated to the remainder of Finland.
The treaty did not require Finland to empty the ceded territory, but almost nobody was willing to stay, and almost 100% of the affected population chose to relocate, taking their belongings with them. Only the buildings and machinery were to be left behind intact as per the Peace Treaty, which for the most part also took place.
During the Continuation War, some 260,000 of the displaced population returned home. In June 1944, Finnish troops partially withdrew from the ceded areas again as a result of the Soviet Fourth strategic offensive. Simultaneously, the population was again evacuated.
The Paris Peace Treaties of 1947 finally confirmed the Finnish loss of the territory. The evacuees were permanently settled in Finland. The government of Finland subsidized the resettlement in two ways:
Since the 1990s, some associations have demanded the return of Karelia to Finland.