15 December 1917 - An armistice between Russia and the Central Powers is signed, and Russian leaves World War I.
15 March 1917: Tsar Nicholas II abdicates and also removes his son from the succession. A Provisional Government is formed to replace the tsarist government. (13h 2min, mar 15, 1917 y – 5h 10min, dec 15, 1917 y)