Leon Trotsky was a Soviet military leader, political theorist, and Bolshevik politician who succeeded Vladimir Lenin as Premier. He was the head of the 'Internationalist' faction of the party, which largely subscribed to his idea of "Permanent Revolution."
Born in 1879 to a Jewish Ukrainian family, Trotsky allied himself with the Bolshevik revolutionaries during the First Russian Civil War. In the aftermath, and following Lenin's death in 1924, the Politburo elected Trotsky to become the new Premier. He was immediately faced with opposition, leading to the CPSU falling to factionalism. Trotsky assumed control of the 'Internationalist' faction, which adhered to his ideas, and wished to spread the Communist revolution throughout the world.
By 1939, a failed Communist uprising in Poland led to the country's occupation by Nazi Germany. Trotsky, angered by the act, declared war on Germany, leading to the beginning of World War II. Most Western capitalist nations allied with Germany, and waged a 6-year long war against the Soviets. The war came to an end in 1945, when an atomic bomb was dropped on a Moscow, under the orders of US President Douglas MacArthur. A large proportion of the Soviet leadership, including Trotsky, was killed during the attack, and the Second World War was declared over. Lavrentiy Beria and the 'Nationalist' faction of the party took control of the country in the aftermath, and started to dismantle all of his work.