(1879-1940) Marxist-Leninist revolutionary and theorist, and one of the leaders of the Bolshevik Revolution in Russia. Also quite gifted in abstract mathematics, but he spurned a life of numbers in favor of revolt. During the civil war, Trotsky organized and led the vaunted Red Army. After Lenin's death and the subsequent rise of Stalin, Trotsky became the leader of the Left Opposition to Stalin's bureaucratic regime. He lost the power struggle, and was expelled from the USSR. Trotsky believed in a democratic (interal democracy only) Bolshevik Party and some participation of the proletariat in economic decisions. Also crucial to Trotskyism is the theory of Permanent Revolution, the idea that an isolated USSR could not have stood on its own, but needed aid from a Socialist Western Europe - compare to Stalin's "Socialism in one country." With the failure of the Spartakus revolt in Berlin and the French general strike of 1920, that aid did not come. A Stalinist agent buried an ice pick in his head in 1940.

Trotsky was something of a Menshevik before the revolution. His earlier pamphlets warned against what Russia would become; later, inexplicably, he would become a Bolshevik. His betrayal of the ideals of which he had formerly adhered so firmly culminated in the Kronstadt massacre.