18 December 1878 – 5 March 1953 was a Soviet revolutionary and politician of Georgian ethnicity. He ruled the Soviet Union from the mid-1920s until his death in 1953, holding the titles of General Secretary of the Communist Party of the Soviet Union from 1922 to 1952 and the nation's Premier from 1941 to 1953. Initially presiding over an oligarchic one-party regime that governed by plurality, he became the de facto dictator of the Soviet Union by the 1930s. Ideologically committed to the Leninist interpretation of Marxism, Stalin helped to formalise these ideas as Marxism–Leninism while his own policies became known as Stalinism.
Born to a poor family in Gori, Russian Empire, Stalin began his revolutionary career in his youth by joining the Marxist Russian Social Democratic Labour Party. There, he edited the party's newspaper, Pravda, and raised funds for Vladimir Lenin's Bolshevik faction via robberies, kidnappings, and protection rackets. Repeatedly arrested, he underwent several internal exiles. After the Bolsheviks seized power in Russia during the 1917 October Revolution, Stalin joined the party's governing Politburo where he was instrumental in overseeing the Soviet Union's establishment in 1922. As Lenin fell ill and then died in 1924, Stalin assumed leadership over the country. During Stalin's rule, "Socialism in One Country" became a central tenet of the party's dogma, and Lenin's New Economic Policy was replaced with a centralized command economy. Under the Five-Year Plan system, the country underwent collectivisation and rapid industrialization but also experienced significant disruptions in food production that contributed to the famine of 1932–33. To eradicate those regarded as "enemies of the working class", Stalin instituted the "Great Purge" in which over a million were imprisoned and at least 700,000 were executed from 1934 to 1939.
Stalin's government promoted Marxism–Leninism abroad through the Communist International and supported anti-fascist movements throughout Europe during the 1930s, particularly in the Spanish Civil War. In 1939 it signed a non-aggression pact with Nazi Germany, resulting in their joint invasion of Poland. Germany ended the pact by invading the Soviet Union in 1941. Despite initial setbacks, the Soviet Red Army halted the German incursion and captured Berlin in 1945, ending World War II in Europe. The Soviets annexed the Baltic states and helped establish Soviet-aligned governments throughout most of Central and Eastern Europe and in China and North Korea. The Soviet Union and the United States emerged from the war as the two world superpowers. Tensions escalated into a Cold War between the Soviet-backed Eastern Bloc and U.S.-backed Western Bloc. Stalin led his country through its post-war reconstruction, during which it developed a nuclear weapon in 1949. In these years, the country experienced another major famine. Stalin died in 1953 and was eventually succeeded by Nikita Khrushchev, who denounced his predecessor and initiated a de-Stalinisation process throughout Soviet society.
Widely considered one of the 20th century's most significant figures, Stalin was the subject of a pervasive personality cult within the international Marxist–Leninist movement, for whom Stalin was a champion of socialism and the working class. Since the 1991 dissolution of the Soviet Union, Stalin has retained popularity in Russia and Georgia as a victorious wartime leader who established the Soviet Union as a major world power. Conversely, his totalitarian government has been widely condemned for overseeing mass repressions, ethnic cleansing, hundreds of thousands of executions, and famines which caused the deaths of millions.