Vladimir Ilyich Lenin (Russian: Владимир Ильич Ленин, IPA: [vɫɐˈdʲimʲɪr ɪlʲˈjit͡ɕ ˈlʲenʲɪn] ; born 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 the leader of the Russian Soviet Federative Socialist Republic from 1917, and then concurrently as Premier of the Soviet Union from 1922, until his death. Under his administration, the Russian Empire was dissolved and replaced by the Soviet Union, a one-party socialist state; industry and businesses were nationalized, with widespread societal reform implemented. Politically a Marxist, his theoretical contributions to Marxist thought are known as Leninism, which coupled with Marxian economic theory have collectively come to be known as Marxism–Leninism.Born to a wealthy middle-class family in Simbirsk, Lenin gained an interest in revolutionary leftist politics following the execution of his brother Aleksandr in 1887. Expelled from Kazan State University for participating in anti-Tsarist protests, he devoted the following years to a law degree and to radical politics, becoming a Marxist. In 1893 he moved to St Petersburg, and became a senior figure in the Russian Social Democratic Labour Party (RSDLP). Arrested for sedition and exiled to Siberia for three years, he married Nadezhda Krupskaya, and fled to Western Europe, living in Germany, France, England, and Switzerland, where he became known as a prominent party theorist. In 1903, he took a key role in the RSDLP schism, leading the Bolshevik faction against Julius Martov's Mensheviks. Briefly returning to Russia during the Revolution of 1905, he encouraged violent insurrection and later campaigned for the First World War to be transformed into a Europe-wide proletariat revolution. After the 1917 February Revolution ousted the Tsar he returned to Russia.Lenin played a senior role in orchestrating the October Revolution in 1917, which led to the overthrow of the Provisional Government and the establishment of the Russian Socialist Federative Soviet Republic, the world's first constitutionally socialist state. Immediately afterwards, the new government under Lenin's leadership proceeded to implement socialist reforms, including the transfer of estates and crown lands to workers' soviets. He supported world revolution and immediate peace with the Central Powers, agreeing to a punitive treaty that turned over a significant portion of the former Russian Empire to Germany. The treaty was voided after the Allies won the war. In 1921 Lenin proposed the New Economic Policy, a system of state capitalism that started the process of industrialisation and recovery from the Civil War. In 1922, the Russian SFSR joined former territories of the Russian Empire in becoming the Soviet Union, with Lenin elected as its leader.After his death, Marxism–Leninism developed into a variety of schools of thought, namely Stalinism, Trotskyism and Maoism. Lenin remains a controversial and highly divisive world figure. Detractors label him a dictator whose administration oversaw multiple human rights abuses, while supporters reject this criticism and promote him as a champion of the working class. Lenin had a significant influence on the international Communist movement and was one of the most influential and controversial figures of the 20th century.