The Finnish War, fought between 1808 and 1809, was a conflict between the Kingdom of Sweden and the Russian Empire. The war began when Russia invaded Finland, which was then a part of Sweden. The conflict aimed to secure Russian control over the region and resulted in significant territorial changes. The war concluded with the Treaty of Fredrikshamn, where Sweden ceded Finland to Russia. This led to the establishment of the Grand Duchy of Finland, which became an autonomous part of the Russian Empire. The war had lasting effects on Finnish identity and governance, shaping the future of Finland.