The Russian Civil War 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, opposed the Reds, the Whites and foreign interventionists. Thirteen foreign nations intervened against the Red Army, notably the former Allied military forces from the just-concluded 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.