Leon Trotsky (Russian pronunciation: ( listen); 7 November 1879 – 21 August 1940), born Lev Davidovich Bronshtein, was a Russian Marxist revolutionary and theorist, Soviet politician, and the founder and first leader of the Red Army.
Trotsky was initially a supporter of the Menshevik faction of the Russian Social Democratic Labour Party. He joined the Bolsheviks immediately prior to the 1917 October Revolution, and eventually became a leader within the Party, second only to Vladimir Lenin. During the early days of the Soviet Union, he served first as People's Commissar for Foreign Affairs and later as the founder and commander of the Red Army, and People's Commissar of War. He was a major figure in the Bolshevik victory in the Russian Civil War (1918–20). He was also among the first members of the Politburo.
After leading a failed struggle of the Left Opposition against the policies and rise of Joseph Stalin in the 1920s and the increasing role of bureaucracy in the Soviet Union, Trotsky was successively removed from power, expelled from the Communist Party, deported from the Soviet Union and assassinated on Stalin's orders. An early advocate of Red Army intervention against European fascism, Trotsky also opposed Stalin's non-aggression pact with Adolf Hitler in the late 1930s.