The siege of Perekop, also known as the Perekop-Chongar Operation, was a battle of the Southern Front in the Russian Civil War from 7 to 17 November 1920. The White movement's stronghold on the Crimean Peninsula was protected by the Chongar fortification system along the strategic Isthmus of Perekop and the Syvash, from which the Crimean Corps under General Yakov Slashchov repelled several Red Army invasion attempts in early 1920. The Southern Front of the Red Army and the Revolutionary Insurgent Army of Ukraine, under the joint command of Mikhail Frunze, launched an offensive on Crimea with an invasion force four-times larger than the defenders, the White Russian Army under the command of General Pyotr Wrangel. Despite suffering heavy losses, the Reds broke through the fortifications, and the Whites were forced into retreat southwards. Following their defeat at the siege of Perekop, the Whites evacuated from the Crimea, dissolving the Army of Wrangel and ending the Southern Front in Bolshevik victory.

The Revolutionary Insurgent Army of Ukraine, also known as Makhnovtsi, named after their leader Nestor Makhno, was an anarchist army formed largely of Ukrainian peasants and workers during the Russian Civil War of 1917–1922. They protected the operation of "free soviets" and libertarian communes by the Makhnovshchina, an attempt to form a stateless anarcho-communist society from 1918 to 1921 during the Ukrainian War of Independence.