Contemporary Karelia, located on both sides of the Finnish-Russian border, has been inhabited by some group speaking a Baltic-Finnish language for at least 1,000 years. The Karelians were first mentioned in the Scandinavian sagas (Egil-saga) in 874 and later on in the so-called Novgorodian Chronicle in 1143, when they took part in a military invasion against the Western Finnish tribes. In the thirteenth century the Karelians inhabited large areas around Lake Ladoga, some areas of eastern Finland, the Karelian Isthmus, and areas around the White Sea and Lake Onega. This area became a battlefield between Novgorod (later Muscovy) and Sweden and was divided. The same division has been maintained in varying forms in the twentieth century. With Finnish independence in 1917, Border Karelia remained part of Finland. The Karelian Autonomous Republic was established in 1923 in the new socialist state out of the old Russian Karelia, succeeding the Karelian Labor Commune (Karel'skaja Trudovaja Kommuna) formed in 1920. In 1940 the area of the autonomous republic and the areas ceded by Finland to the USSR after the Russo-Finnish War formed the Karelian-Finnish Soviet Socialist Republic (Karelo-Finskaja SSR), which was again changed in 1956 to an autonomous republic. During World War II Soviet Karelia was occupied by German and Finnish forces.
Following World War II, Border Karelia and the Karelian Isthmus were ceded to the USSR. Thus the Finnish Karelians were displaced from their old Karelian location.