Kolchak was born into a noble family. He studied at the Naval Cadet Corps (1894), served on warships in the Baltic Sea and the Pacific Ocean. He was engaged in a number of Russian polar expeditions in the early 20th century. A participant of the Russo-Japanese War and World War I. In June 1916, he was promoted to Vice Admiral and appointed Commander of the Black Sea Fleet.

In June 1917, he left the post of Commander of the fleet and departed for Petrograd. Soon the Provisional Government appointed Kolchak the Head of the Russian naval mission and sent him to the United States. On his way back to Russia via Japan, he learned about the October coup, which caused a highly negative reaction on his part.

In May 1918, he was appointed Chief Inspector of the security guards of the Chinese Eastern Railway (CER), combining this post with that of the leader of all Russian armed forces in its alienation zone. However, he failed to subdue the detachments of atamans Grigory Semyonov and Ivan Kalmykov and soon left his post. On the way to the South of Russia to join the Volunteer Army, in mid-October 1918 he stopped in Omsk. Here, after a series of negotiations, he accepted the offer of General Vasily Boldyrev, Commander-in-Chief of the Provisional All-Russian Government (Ufa Directorate)’s troops to take the post of Minister of War and Navy and took office on November 7.

After the military coup in Omsk on November 18, 1918, the All-Russian Council of Ministers headed by Pyotr Vologodsky, decided to entrust Aleksander Kolchak the exercise of supreme power temporarily assigning him the title of Supreme Ruler of Russia (the Russian State). At the same time, he was promoted to full Admiral and assumed the post of Supreme Leader and Commander-in-Chief of All Russian Land and Naval Forces.

Kolchak’s authorities were recognized by the leaders of the main anti-Bolshevik formations in the south, north-west, and north of Russia. In the spring of 1919, Kolchak’s forces succeeded in the offensive against the troops of the Eastern Front of the Workers’ and Peasants’ Red Army and reached the approaches to Kazan and Samara. However, in the summer and autumn of 1919, the Eastern Front of the Russian Army suffered a succession of serious defeats at the hands of the Reds. The position of the Whites was aggravated by massive anti-Kolchak uprisings, that swept Siberia in 1919.

In the context of military setbacks, he found himself in political isolation. Due to the aggravation of relations with the Czechoslovak Legion the train of the Supreme Ruler was stopped and blocked in Nizhneudinsk. On January 4, 1920, Kolchak signed a decree to announce his intention to transfer the powers of the “Supreme All-Russian Power” to Anton Denikin. The allied command guaranteed Kolchak security, however, the Czechoslovak Legion’s leadership handed the admiral over to the Political Center in Irkutsk. Kolchak was arrested and after the power in the city passed to the Bolshevik Military Revolutionary Committee, on the night of February 6–7, 1920, he was shot.