| August 1914 | Russia enters World War I |
| 1916–1917 | Tsarist government in crisis |
| March 1917 | February Revolution; establishment of provisional government; tsar abdicates |
| April 1917 | Lenin returns from exile |
| July 1917 | Bolshevik attempt to seize power fails |
| October 1917 | Bolsheviks gain a majority in the Petrograd Soviet |
| November 6–7, 1917 | Bolsheviks seize power; Lenin named head of new Communist government |
| 1918–1920 | Civil war |
| March 1918 | Treaty of Brest-Litovsk; Trotsky becomes head of the Red Army |
| 1920 | Civil war ends; Lenin and Bolshevik-Communists take control of Russia |