Born to a wealthy Ukrainian-Jewish family in Yanovka (present-day Bereslavka in Ukraine), 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. During the Russian Social Democratic Labour Party 1903 ideological split he sided with Julius Martov's Mensheviks against Lenin's Bolsheviks. 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 years working in 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. As chairman of the Petrograd Soviet, he played a key role in the October Revolution of November 1917 which overthrew the new Provisional Government.