The primary cause of the Russian Civil War, which lasted from 1917 to 1922, was the power struggle between the Bolshevik government and various factions opposing it, including the White Army, which comprised monarchists, liberals, and other anti-Bolshevik groups. Following the October Revolution in 1917, where the Bolsheviks seized power, the country was plunged into civil conflict. Other contributing factors included widespread discontent over land reforms, national independence movements, and economic turmoil exacerbated by World War I. The civil war ultimately resulted in the establishment of the Soviet Union and shaped the course of Russian history in the 20th century.