Excess mortality in the Soviet Union under Joseph Stalin in the context of "Gulag"

Russia, or the Russian Federation, is a country in Eastern Europe and North Asia. It is the largest country in the world, spanning eleven time zones and sharing land borders with fourteen countries. With a population of over 140 million, Russia is the most populous country in Europe and the ninth-most populous country in the world. It is a highly urbanised country, with sixteen of its urban areas having more than 1 million inhabitants. Moscow, the most populous metropolitan area in Europe, is the capital and largest city of Russia; and Saint Petersburg is its second-largest city and cultural centre.

Human settlement on the territory of modern Russia dates back to the Lower Paleolithic. The East Slavs emerged as a recognised group in Europe between the 3rd and 8th centuries AD. The first East Slavic state, Kievan Rus', arose in the 9th century, and in 988, it adopted Orthodox Christianity from the Byzantine Empire. Kievan Rus' ultimately disintegrated; the Grand Duchy of Moscow led the unification of Russian lands, leading to the proclamation of the Tsardom of Russia in 1547. By the early 18th century, Russia had vastly expanded through conquest, annexation, and the efforts of Russian explorers, developing into the Russian Empire, which remains the third-largest empire in history. However, with the Russian Revolution in 1917, Russia's monarchic rule was abolished and eventually replaced by the Russian SFSR—the world's first constitutionally socialist state. Following the Russian Civil War, the Russian SFSR established the Soviet Union with three other Soviet republics, within which it was the largest and principal constituent. The Soviet Union underwent rapid industrialisation in the 1930s, amidst the deaths of millions under Joseph Stalin's rule, and later played a decisive role for the Allies in World War II by leading large-scale efforts on the Eastern Front—rising as a global superpower. With the onset of the Cold War, it competed with the United States for ideological dominance and international influence. The Soviet era of the 20th century saw some of the most significant Russian technological achievements, including the first human-made satellite and the first human expedition into outer space.

Joseph Vissarionovich Stalin (né Dzhugashvili; 18 December [O.S. 6 December] 1878 – 5 March 1953) was a Soviet politician, dictator and revolutionary who led the Soviet Union from 1924 until his death in 1953. His rule oversaw mass atrocities that caused an estimated 20 million deaths, and he is widely considered one of the most brutal despots of the modern era. He held office as General Secretary of the Communist Party from 1922 to 1952 and as premier from 1941 until his death. Despite initially governing the country as part of a collective leadership, he eventually consolidated power to become a dictator by the 1930s. Stalin codified the party's official interpretation of Marxism as Marxism–Leninism, and his version of it is referred to as Stalinism.

Born into a poor Georgian family in Gori, Russian Empire, Stalin attended the Tiflis Theological Seminary before joining the Marxist Russian Social Democratic Labour Party. He raised funds for Vladimir Lenin's Bolshevik faction through bank robberies and other crimes, and edited the party's newspaper, Pravda. He was repeatedly arrested and underwent several exiles to Siberia. After the Bolsheviks seized power in the October Revolution of 1917, Stalin served as a member of the Politburo, and from 1922 used his position as General Secretary to gain control over the party bureaucracy. After Lenin's death in 1924, Stalin won the leadership struggle over rivals including Leon Trotsky. Stalin's doctrine of socialism in one country became central to the party's ideology, and his five-year plans starting in 1928 led to forced agricultural collectivisation, rapid industrialisation, and a centralised command economy. His policies contributed to a famine in 1932–1933 which killed millions, including in the Holodomor in Ukraine. Between 1936 and 1938, Stalin executed hundreds of thousands of his real and perceived political opponents in the Great Purge. Under his regime, an estimated 18 million people passed through the Gulag system of forced labour camps, and more than six million people, including kulaks and entire ethnic groups, were deported to remote areas of the country.

The history of the Soviet Union between 1927 and 1953, commonly referred to as the Stalin Era or the Stalinist Era, covers the period in Soviet history from the establishment of Stalinism through victory in the Second World War and down to the death of Joseph Stalin in 1953. Stalin sought to destroy his enemies while transforming Soviet society with central planning, in particular through the forced collectivization of agriculture and rapid development of heavy industry. Stalin consolidated his power within the party and the state and fostered an extensive cult of personality. Soviet secret-police and the mass-mobilization of the Communist Party served as Stalin's major tools in molding Soviet society. Stalin's methods in achieving his goals, which included party purges, ethnic cleansings, political repression of the general population, and forced collectivization, led to millions of deaths: in Gulag labor camps and during famine.

World War II, known as "the Great Patriotic War" by Soviet historians, devastated much of the USSR, with about one out of every three World War II deaths representing a citizen of the Soviet Union. In the course of World War II, the Soviet Union's armies occupied Eastern Europe, where they established or supported Communist puppet governments. By 1949, the Cold War had started between the Western Bloc and the Eastern (Soviet) Bloc, with the Warsaw Pact (created 1955) pitched against NATO (created 1949) in Europe. After 1945, Stalin did not directly engage in any wars, continuing his totalitarian rule until his death in 1953.