Joseph Stalin or Iosif Vissarionovich Stalin (December 18, 1878 – March 5, 1953) is the de facto leader of the Soviet Union from the mid-1920s until his death in 1953.

Among the Bolshevik revolutionaries who take part in the Russian Revolution of 1917, Stalin is appointed General Secretary of the party's Central Committee in 1922.

He subsequently manages to consolidate power following the 1924 death of Vladimir Lenin through expanding the functions of his role, all the while eliminating any opposition.

He holds this nominal post until abolishing it in 1952, concurrently serving as the Premier of the Soviet Union after establishing the position in 1941.

Under Joseph Stalin's rule, the concept of "socialism in one country" becomes a central tenet of Soviet society.

He replaces the New Economic Policy introduced by Lenin in the early 1920s with a highly centralizes command economy, launching a period of industrialization and collectivization that results in the rapid transformation of the USSR from an agrarian society into an industrial power.

However, the economic changes coincide with the imprisonment of millions of people in Soviet correctional labor camps and the deportation of many others to remote areas The initial upheaval in agriculture disrupts food production and contributes to the catastrophic Soviet famine of 1932–1933, known as the Holodomor in Ukraine.

Later, in a period that lasts from 1936–39, Stalin institutes a campaign against alleged enemies of his regime called the Great Purge, in which hundreds of thousands are executed.

Major figures in the Communist Party, such as the old Bolsheviks, Leon Trotsky, and several Red Army leaders are killed after being convicted of plotting to overthrow the government and Stalin.

In August 1939, Stalin enters into a nonaggression pact with Nazi Germany that divides their influence within Eastern Europe, but Germany later violates the agreement and launches a massive invasion of the Soviet Union in June 1941.

Despite heavy human and territorial losses, Soviet forces manage to halt the Nazi incursion after the decisive battles of Moscow and Stalingrad.

After defeating the Axis powers on the Eastern Front, the Red Army captures Berlin in May 1945, effectively ending the war in Europe for the Allies.

The Soviet Union subsequently emerges as one of two recognized world superpowers, the other being the United States.

The Yalta and Potsdam conferences establish communist governments loyal to the Soviet Union in the Eastern Bloc countries as buffer states, which Stalin deems necessary in case of another invasion.

He also fostersclose relations with Mao Zedong in China and Kim Il-sung in North Korea.

Stalin leads the Soviet Union through its postwar reconstruction phase, which sees a significant rise in tension with the Western world that will later be known as the Cold War.

During this period, the USSR becomes the second country in the world to successfully develop a nuclear weapon, as well as launching the Great Plan for the Transformation of Nature in response to another widespread famine and the Great Construction Projects of Communism.

In the years following his death, Stalin and his regime have been condemned on numerous occasions, most notably in 1956 when his successor Nikita Khrushchev denounced his legacy and initiated a process of de-Stalinization.

He remains a controversial figure today, with many regarding him as a tyrant similar to his wartime enemy Adolf Hitler; however, popular opinion within the Russian Federation is mixed.