There were four main classes in Russian society: [1] the nobility, who spoke French and other European languages; [2] the clergy; [3] the merchants; and [4] the peasants, who made up the largest part of the population. After the Russian Civil War from 1918 to 1921, which killed around 15 million Russians, the Bolsheviks under Lenin emerged victorious and established the Soviet Union. Stalin later took control of the Communist Party and transitioned the Soviet Union to a dictatorship, imposing strict control over both the government and individual lives.