The Russian Revolution of 1917 was a series of events that led to the overthrow of the Tsarist autocracy in Russia. It consisted of two main phases: the February Revolution, which resulted in the abdication of Tsar Nicholas II, and the October Revolution, where the Bolsheviks, led by Vladimir Lenin, seized power. The revolution was driven by widespread discontent with the government, economic hardship, and the impact of World War I. It ultimately led to the establishment of a communist government and significant changes in Russian society, paving the way for the formation of the Soviet Union.