After the revolution Trotsky left Russia for his own safety. In 1917, he returned to Russia because of the Russian Revolution. He helped to bring about communism in Russia and defend it during the Russian Civil War. He was in charge of the army at this time. When the leader of the Bolsheviks (the party who led the revolution) Vladimir Lenin died, Trotsky became involved in a power struggle with Joseph Stalin for the leadership of the party. He lost, and Stalin came to power. He had to leave Russia because of Stalin, who was now his own enemy and wanted to harm Trotsky. In 1938 Trotsky founded the Fourth International. Stalin had one of his spies, Spaniard Ramón Mercarder, stab Trotsky to death in Mexico in 1940.