The MGB (Russian: 'МГБ'), an initialism for Ministerstvo gosudarstvennoy bezopasnosti SSSR (Russian: Министе́рство госуда́рственной безопа́сности СССР, IPA: [mʲɪnʲɪˈsʲtʲɛrstvə ɡəsʊˈdarstvʲɪnnəj bʲɪzɐˈpasnəsʲtʲɪ], translated in English as Ministry for State Security), was the name of the Soviet intelligence agency from 1943 to 1956.
The MGB was just one of many incarnations of the Soviet State Security apparatus. After the revolution, the Bolsheviks relied on a strong political police or security force to support and control their regime. During the Russian Civil War, the Cheka were in power, relinquishing it to the less violent State Political Directorate (GPU) in 1922 after the fighting was over. The GPU was then renamed The People’s Commissariat for Internal Affairs (NKVD) in 1934. From the mid-1930s and until the creation of the KGB, this “Organ of State Security” was re-organized and renamed multiple times depending on the needs and fears of the leadership. In 1941, the state-security function was separated from the NKVD and became the People's Commissariat for State Security (NKGB), only to be reintegrated a few months later during the Nazi invasion of the Soviet Union. In 1943, the NKGB was once again made into an independent organization in response to the Soviet occupation of parts of Eastern Europe. SMERSH—anecdotally derived from a phrase translated as "Death to Spies"—which was designed to be a counter-intelligence unit within the Red Army to ensure the loyalty of the army personnel. Following the end of the war, both the NKVD and the NKGB were converted to ministries and redubbed the Ministry for Internal Affairs (MVD) and the Ministry for State Security (MGB). The MGB and MVD merged again in 1953, orchestrated by Lavrenty Beria, who was then arrested and executed. The KGB took on the mantle of the NKGB/ MGB and, in 1954, broke off from the reformed MVD.