The Russian Civil War (1917-1922/3) was a multi-sided conflict that takes place within the borders of the former Russian Empire following the collapse of the Russian provisional government and the Bolshevik takeover of Petrograd (Saint Petersburg).The main hostilities take place between the Bolshevik Red Army, and the loosely-allied anti-Bolshevik forces, known as the White Army.

Many foreign armies also participate, among which of note is the allied intervention in the Russian Civil War.

Additionally many foreigners volunteer to fight on one or other of the sides.

Other forces include various nationalist and regional movements such as the Ukrainian nationalist Green Army, other political movements such as the Ukrainian anarchist Black Guards, and independent warlords such as Ungern von Sternberg.

These forces sometimes fight against both Reds and Whites, sometimes side with one of the two, and sometimes switch sides.

Additionally the warring sides spill over Russia's borders into Persia, Mongolia and the Russian borders themselves are unclear in the cases of new states split from Russia after the revolution.The most intense fighting takes place from 1918 to 1920.

In Soviet historiography the end of the Civil War is dated to October 25, 1922 when the Red Army occupies Vladivostok, previously held by the Provisional Priamur Government.

The last enclave of the White Forces is the Ayano-Maysky District on the Pacific coast, where General Anatoly Pepelyayev does not capitulate until June 17, 1923.