The Russian Civil War (Russian: Гражданская война в России, tr. Grazhdanskaya voyna v Rossiya) was a multi-party civil war in the former Russian Empire immediately after the two Russian revolutions of 1917, as many factions vied to determine Russia's political future. The two largest combatant groups were the Red Army, fighting for the Bolshevik form of socialism led by Vladimir Lenin, and the loosely allied forces known as the White Army, which included diverse interests favouring political monarchism, capitalism and social democracy, each with democratic and anti-democratic variants. In addition, rival militant socialists, notably Makhnovia anarchists and Left SRs, as well as non-ideological Green armies, fought against both the Reds and the Whites.v Thirteen foreign nations intervened against the Red Army, notably the former Allied military forces from the World War with the goal of re-establishing the Eastern Front. Three foreign nations of the Central Powers also intervened, rivaling the Allied intervention with the main goal of retaining the territory they had received in the Treaty of Brest-Litovsk.
After the revolution the Bolsheviks swept through Russia nearly unopposed. The republic had collapsed after the Soviets were given all political power, leaving no solid resistance to the Reds. In May 1918, the Czech Legion in Russia revolted in Siberia. Reacting to this, the Allies began an intervention in Northern Russia and Siberia. This, combined with the creation of the Provisional All-Russian Government, saw the reduction of the Bolsheviks to most of European Russia and parts of Central Asia. In November, Alexander Kolchak launched a coup to take control of the Russian State, establishing a de facto military dictatorship.
The White Army launched several attacks from the East in March, the South in July, and West in October 1919. These advances were later checked with the Eastern Front counteroffensive, the Southern Front counteroffensive, and defeat of the Northwestern Army. The White Movement also suffered greater loss as the Allies pulled back from North and South Russia. With the main base of the Russian SFSR secured, the Soviets could now strike back.
The armies under Kolchak were eventually forced on a mass retreat east. Soviet forces advanced east, despite encountering resistance in Chita, Yakut and Mongolia. Soon the Red Army split the Don and Volunteer armies, forcing an evacuation in Novorossiysk in March and Crimea in November 1920. White resistance was sporadic for two years until the collapse of the White Army in Yakutsk in June 1923, but went on in Central Asia and Khabarovsk Krai. There were an estimated 7 to 12 million casualties during the war, mostly civilians.
Many pro-independent movements emerged after the break-up of the Russian Empire and fought in the war. Several parts of the former Russian Empire—Finland, Estonia, Latvia, Lithuania, and Poland—were established as sovereign states, with their own civil wars and wars of independence. The rest of the former Russian Empire was consolidated into the Soviet Union shortly afterwards.