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. Despite Lenin's opposition, he assumed leadership over the country shortly after the former's death in 1924. During Stalin's rule, "Socialism in One Country" became a central tenet of the party's dogma, and Lenin's New Economic Policy was abandoned in favour of a centralized command economy. Under the Five-Year Plan system, the country underwent 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 pro-Soviet Marxist–Leninist governments throughout Central and Eastern Europe. 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.S.-backed Western Bloc known as the Cold War. 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 peaking in the 1952–53 Doctors' plot. 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. 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, hundreds of thousands of executions, and millions of deaths by famine.
Stalin was born Ioseb Besarionis dze Jughashvili in the Georgian town of Gori on 18 December 1878. He was the son of Besarion Jughashvili and Ekaterine "Keke" Geladze, who had married in May 1872, and had lost two sons in infancy prior to Stalin's birth. They were ethnically Georgian and Stalin grew up speaking the Georgian language. Gori was then part of the Russian Empire, and was home to a population of 20,000, the majority of whom were Georgian but with Armenian, Russian, and Jewish minorities. Stalin was baptised on 29 December. He was nicknamed "Soso", a diminutive of "Ioseb". Besarion was a cobbler and in the early years of their marriage, the couple prospered. He did not adapt to changing footwear fashions and his business began to fail. The family soon found themselves living in poverty, moving through nine different rented rooms in ten years.
Besarion became an alcoholic, and drunkenly beat his wife and son. To escape the abusive relationship, Keke took Stalin and moved into the house of a family friend, Father Christopher Charkviani. She worked as a house cleaner and launderer for several local families who were sympathetic to her plight. Keke was determined to send her son to school, something that none of the family had previously achieved. In late 1888, aged 10 he enrolled at the Gori Church School. This was normally reserved for the children of clergy, although Charkviani ensured that Stalin received a place. Stalin excelled academically, displaying talent in painting and drama classes, writing his own poetry, and singing as a choirboy. He got into many fights, and a childhood friend later noted that Stalin "was the best but also the naughtiest pupil" in the class. Stalin faced several severe health problems; in 1884, he contracted smallpox and was left with facial pock scars. Aged 12, he was seriously injured after being hit by a phaeton, resulting in a lifelong disability to his left arm.
At his teachers' recommendation, Stalin proceeded to the Spiritual Seminary in Tiflis. He enrolled at the school in August 1894, enabled by a scholarship that allowed him to study at a reduced rate. Here he joined 600 trainee priests who boarded at the seminary. Stalin was again academically successful and gained high grades. He continued writing poetry; five of his poems were published under the pseudonym of "Soselo" in Ilia Chavchavadze's newspaper Iveria ('Georgia'). Thematically, they dealt with topics like nature, land, and patriotism. According to Stalin's biographer Simon Sebag Montefiore, they became "minor Georgian classics", and were included in various anthologies of Georgian poetry over the coming years. As he grew older, Stalin lost interest in his studies; his grades dropped, and he was repeatedly confined to a cell for his rebellious behaviour. Teachers complained that he declared himself an atheist, chatted in class and refused to doff his hat to monks.
Stalin joined a forbidden book club active at the school; he was particularly influenced by Nikolay Chernyshevsky's 1863 pro-revolutionary novel What Is To Be Done?. Another influential text was Alexander Kazbegi's The Patricide, with Stalin adopting the nickname "Koba" from that of the book's bandit protagonist. He also read Capital, the 1867 book by German sociological theorist Karl Marx. Stalin devoted himself to Marx's socio-political theory, Marxism, which was then on the rise in Georgia, one of various forms of socialism opposed to the empire's governing Tsarist authorities. At night, he attended secret workers' meetings, and was introduced to Silibistro "Silva" Jibladze, the Marxist founder of Mesame Dasi ('Third Group'), a Georgian socialist group. In April 1899, Stalin left the seminary and never returned, although the school encouraged him to come back.