The start of the Russian Revolution in 1917 was sparked by a combination of social, economic, and political discontent among the Russian populace, particularly due to World War I's strains. Food shortages, military failures, and widespread dissatisfaction with the Tsarist regime contributed to mass protests and strikes in Petrograd. These events, including the February Revolution, led to the abdication of Tsar Nicholas II and the eventual rise of the Bolsheviks. The revolution fundamentally changed Russia, leading to the establishment of a communist government and altering the course of history for the 20th century.