The Swedish-Finnish War took place from 1808 to 1809 between the Kingdom of Sweden and the Russian Empire. The conflict arose as Russia sought to expand its influence in the region, leading to military confrontations in Finland, which was then a part of Sweden. The war ended with the Treaty of Fredrikshamn in 1809, resulting in Sweden ceding Finland to Russia. This marked the beginning of Finland's status as an autonomous Grand Duchy within the Russian Empire, significantly altering the political landscape of Northern Europe.