Gulag

System of Soviet labour camps and prisons that from the 1920s to the mid-1950s housed millions of political prisoners and criminals. The term (an abbreviation of the Russian words for Chief Administration of Corrective Labour Camps) was largely unknown in the West until the 1973 publication of Aleksandr Solzhenitsyn's Gulag Archipelago.

The Gulag consisted of hundreds of camps, under the control of the secret police, where prisoners felled timber, worked in the mines, or laboured on construction projects. At least 10% died each year from harsh working conditions, inadequate food, and summary executions. The Gulag reached its height in the years of collectivization of Soviet agriculture (1929–32), during Joseph Stalin's purges (1936–38), and immediately after World War II, shrinking only after Stalin's death in 1953. An estimated 15–30 million Russians died in the camps.