Lev Davidovich Bronstein, better known as Leon Trotsky, was a Ukrainian-Russian Marxist revolutionary, political theorist and politician. Ideologically a communist, he developed a variant of Marxism which has become known as Trotskyism.
Born to a wealthy Ukrainian-Jewish family in Yanovka, Trotsky embraced Marxism after moving to Nikolayev in 1896. In 1898 Tsarist authorities arrested him for revolutionary activities and subsequently exiled him to Siberia. He escaped from Siberia in 1902 and moved to London, where he befriended Vladimir Lenin. In 1903, he sided with Julius Martov's Mensheviks against Lenin's Bolsheviks during the Russian Social Democratic Labour Party's initial organisational split. Trotsky helped organize the failed Russian Revolution of 1905, after which he was again arrested and exiled to Siberia. He once again escaped and spent the following 10 years working in Britain, Austria, Switzerland, France, Spain, and the United States. After the 1917 February Revolution brought an end to the Tsarist monarchy, Trotsky returned to Russia and became a leader in the Bolshevik faction.