Alexander Kolchak (1874 - 7 February 1920) Imperial Russian admiral, military leader and polar explorer who served in the Imperial Russian Navy and fought in the Russo-Japanese War of 1904-1905 and the First World War. During the Russian Civil War of 1917-1922 he established an anti-communist government in Siberia -- later the Provisional All-Russian Government -- and became recognised as the 'Supreme Leader and Commander-in-Chief of All Russian Land and Sea Forces' by the other leaders of the White movement from 1918 to 1920. His government was based in Omsk, in southwestern Siberia.