After the Bolsheviks gained power in the October Revolution of 1917 and established the Russian Soviet Republic, Stalin sat on the governing Politburo during the Russian Civil War and helped form the Soviet Union in 1922.
Despite Lenin's opposition, Stalin consolidated power following the former's death in 1924.
Stalin died in 1953 and was 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.
According to the historian Oleg Khlevniuk, Stalin "filled an important role [in the October Revolution]...
Believing that victory was assured by numerical superiority, he sent large numbers of Red Army troops into battle against the region's anti-Bolshevik White armies, resulting in heavy losses; Lenin was concerned by this costly tactic.
The Soviet Union and the United States emerged as the two world superpowers, and a period of tensions began between the Soviet-backed Eastern Bloc and U. 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 and a period of antisemitism, which reached its peak in the 1952–1953 Doctors' plot.
Ideologically a Marxist and a Leninist, Stalin helped to formalise these ideas as Marxism–Leninism while his own policies became known as Stalinism.
Raised into a poor family in Gori, Russian Empire, as a youth Stalin joined the Marxist Russian Social Democratic Labour Party.