Vladimir Ilyich Ulyanov (22 April [O.S. 10 April] 1870 21 January 1924) was a Russian communist revolutionary, politician, and political theorist. He served as head of government of the Russian Soviet Federative Socialist Republic from 1917 to 1924 and of the Soviet Union from 1922 to 1924. Under his administration, Russia became a one-party socialist state; all land, natural resources, and industry were socialized into public property. Ideologically a Marxist, his political theories are known as Leninism.
Born to a wealthy middle-class family in Simbirsk, Lenin gained an interest in revolutionary socialist politics following his brother's execution in 1887. Expelled from Kazan State University for participating in protests against the Russian Empire's Tsarist regime, he devoted the following years to a law degree. In 1893 he moved to Saint Petersburg and became a senior figure in the Marxist Russian Social Democratic Labour Party (RSDLP). Arrested for sedition and exiled to Shushenskoye for three years, there he married Nadezhda Krupskaya. After his exile he moved to Western Europe, where he became a prominent party theorist through his publications. In 1903, he took a key role in a RSDLP schism over ideological differences, leading the Bolshevik faction against Julius Martov's Mensheviks. Encouraging insurrection during Russia's failed Revolution of 1905, he later campaigned for the First World War to be transformed into a Europe-wide proletarian revolution, which as a Marxist he believed would result in the overthrow of capitalism and its replacement with socialism. After the 1917 February Revolution ousted the Tsar and established a Provisional Government, he returned to Russia to campaign for the new regime's removal by a Bolshevik-led government of the soviets.