Joseph Stalin (, ; March 5, 1953) was General Secretary of the Communist Party of the Soviet Union's Central Committee from 1922 until his death in 1953. He gradually consolidated power and became party leader and dictator of the Soviet Union, established the regime now known as Stalinism.<ref>
Bullock, p. 548, "both dictators".<br />
:Ulam, p. xiv, "the dictator not only deprived".
:Davies, Harris, p.108, "Stalin as dictator".
:Mawdsley, p. 1, "effectively a dictator".
:Overy, p. 17, "and, later, as dictator"</ref>
Following the death of Vladimir Lenin in 1924, Stalin prevailed in a power struggle over Leon Trotsky, who was expelled from the Communist Party and deported from the Soviet Union. Stalin launched a command economy in the Soviet Union replacing the New Economic Policy of the 1920s with Five-Year Plans in 1928 and at roughly the same time, forced rapid industrialization of the largely rural country and collective farming by confiscating the lands of farmers. He derogatorily referred to farmers who refused his reforms as "kulaks", a class of rich peasant which had in actual fact been wiped out by World War I; millions were killed, exiled to Siberia, or died of starvation after their land, homes, meager possessions, and ability to earn an existence from the land were taken to fulfill Stalin's vision of massive "factory farms". While the Soviet Union transformed from an agrarian economy to a major industrial powerhouse in a short span of time, millions of people died from hardships and famine that occurred as a result of the severe economic upheaval and party policies.
At the end of 1930s, Stalin launched the Great Purge, a major campaign of political repression. During his continued repressions, millions of people who were a threat to the Soviet politics or suspected of being such a threat were executed or exiled to Gulag labor camps in remote areas of Siberia or Central Asia, where many more died of disease, malnutrition and exposure. A number of ethnic groups in Russia were forcibly resettled for political reasons. Stalin's rule, reinforced by a cult of personality, fought real and alleged opponents mainly through the security apparatus, such as the NKVD. In the 1950s, Nikita Khrushchev, Stalin's eventual successor, denounced Stalin's rule and the cult of personality, thus initiating the process of "de-Stalinization".
Bearing the brunt of the Nazis' attacks, the Soviet Union under Stalin made the largest and most decisive contribution to the defeat of Nazi Germany during World War II (1939–1945), despite Stalin's policy mistakes before and during the war. These included a devastating internal policy which weakened the Soviet society and strategic blunders during the first period of Great Patriotic War. Additionally the Molotov-Ribbentrop pact, and its secret protocol, cleared the way for Hitler's invasion of Poland in 1939 and the beginning of the war itself.
Under Stalin's leadership, after the war, the Soviet Union went on to achieve recognition as one of just two superpowers in the world. That status lasted for nearly four decades after his death until the dissolution of the Soviet Union. Stalin's rule had long-lasting effects on the features that characterized the Soviet state from the era of his rule to its collapse in 1991.