The Gulag (Russian: ГУЛАГ, tr. GULAG; IPA: [ɡʊˈlak]; acronym of Russian Главное управление лагерей "main administration of the camps", usually translated "Chief Directorate of Camps") was the government agency that administered and controlled the main Soviet forced-labor camp system during the period of Joseph Stalin's rule over the country from the 1930s up until the 1950s.
The first such camps were created in 1918 and the term is widely used to describe any forced-labor camp in the USSR. While the camps housed a wide range of convicts, from petty criminals to political prisoners, large numbers were convicted by simplified procedures, such as NKVD troikas and other instruments of extrajudicial punishment (the NKVD was the Soviet secret police). The Gulag is recognized as a major instrument of political repression in the Soviet Union, based on Article 58 (RSFSR Penal Code). The term is also sometimes used to describe the camps themselves, particularly in the West.
"GULAG" was the acronym for Гла́вное управле́ние лагере́й (Glavnoye upravleniye lagerey), the "Main Camp Administration". It was the short form of the official name Гла́вное управле́ние исправи́тельно-трудовы́х лагере́й и коло́ний (Glavnoye upravleniye ispravityelno-trudovykh lagerey i koloniy), the "Main Administration of Corrective Labor Camps and Labor Settlements". It was administered first by the GPU, later by the NKVD and in the final years by the MVD, the Ministry of Internal Affairs. The first corrective labour camps constructed after the revolution (Solovki) were established in 1918 and they were legalized by a decree "On the creation of the forced-labor camps" on April 15, 1919. The internment system grew rapidly, reaching a population of 100,000 in the 1920s and from the very beginning it had a very high mortality rate.