Karelia, the land of the Karelian peoples, is an area in Northern Europe of historical significance for Finland, Russia, and Sweden. It is currently divided between the Russian Republic of Karelia, the Russian Leningrad Oblast, and Finland (the regions of South Karelia and North Karelia).
Various subdivisions may be called Karelia. Finnish Karelia was a historical province of Finland, now divided between Finland and Russia, often called just Karjala in Finnish. The eastern part of this chiefly Lutheran area was ceded to Russia after the Winter War of 1939-40. This area is the “Karelia” of the Karelian question in Finnish politics. The Republic of Karelia is a Russian federal subject, including the so-called “East Karelia” with a chiefly Russian Orthodox population. Within present-day Finland, Karjala refers to regions of South and North Karelia.
In 1939, the Soviet Union attacked Finland, thus starting the Winter War. The Moscow Peace Treaty of 1940 handed most of Finnish Karelia to the Soviet Union. About 400,000 people, virtually the whole population, had to be relocated within Finland. In 1941, Karelia was liberated for three years during the Continuation War of 1941 to 1944 when East Karelia was occupied by the Finns. The Winter War and the resulting Soviet expansion caused considerable bitterness in Finland, which lost its second biggest city, Viipuri, its industrial heartland along the river Vuoksi, the Saimaa canal that connected central Finland to the Gulf of Finland, access to the fishing waters of Lake Ladoga (Finnish: Laatokka), and made an eighth of her citizens refugees without chance of return.
As a consequence of the peace treaty, the Karelian ASSR was incorporated with the Karelo-Finnish SSR 1941–1956, after which it became an ASSR again. Karelia was the only Soviet republic that was “demoted” from an SSR to an ASSR within the Russian SFSR. Unlike autonomous republics, Soviet republics (in theory) had the constitutional right to secede. The possible fear of secession, as well as the Russian ethnic minority in Karelia may have resulted in its “demotion.” In 1991 the Republic of Karelia was created out of the ASSR.