Admiral Kolchak's early service at the siege of Port Arthur during the Russo-Japanese War led to his participation in the series of reforms instituted within the Russian Navy, and the creation of the Russian Naval General Staff. As an hydrologist of some note, Kolchak was a member of the third polar expedition meant to find a northern sea route to the Far East. He was appointed a member of the Naval General Staff, 1911-14, and captained the Baltic Sea Fleet Flagship at the outbreak of war. As Chief of the Bureau of Operations of the Baltic Fleet in 1915, Kolchak constructed the coastal defence system, and became the youngest naval officer promoted to vice admiral of the Russian Navy on August 1916, after his successes off the Gulf of Riga. He was then assigned as Commander-In-Chief of the Black Sea Fleet, and in 1917, became a supporter of Kerensky's Provisional Government.
In June, 1917, Kolchak resigned, but was sent by Kerensky to the United States to study the US Navy, with a view to the invasion of the Bosporus. En route, he stopped in Britain where he became friendly with Admirals Hall and Jellicoe, but after his US visit, sailed to Japan, arriving shortly after the November Revolution. Kolchak then offered his services to the British Navy after the beginning of the Brest-Litovsk negotiations; his offer was accepted and he was directed to report to duty with British forces in Mesopotamia, a duty station almost immediately changed to Siberia instead. Returning to Siberia, he was appointed Minister of War and Navy in the anti-Bolshevik Socialist government established at Omsk, and then seized control to become Supreme Ruler in a coup d'etat. Kolchak proceeded to antagonise elements within the government, as well as the Czechosolovak Legion which held the Trans-Siberian Railroad, and, after a series of political and military defeats in the summer of 1919, relinquished command to General Anton Denikin on 4 January 1920. He sought Allied protection, but the Czechs instead turned him over to the Bolshevik authorities in Irkutsk where after a somewhat rigourous interrogation, he was executed by firing squad on 2 February 1920, and his body thrown into the Angara River.