Finland had long been the eastern part of the Swedish kingdom when Imperial Russia conquered it in 1809 during the Napoleonic Wars, converting it to an autonomous buffer state in the Russian Empire to protect Saint Petersburg, the imperial capital.

Western Karelia's history is different from the rest of Finland's history. Most of the area paid tribute to the Russian Republic of Novgorod, and was the arena of Swedish-Novgorodian Wars. The southwestern area, from the River Sestra to the River