The Ministry of State Security, abbreviated as MGB, was a ministry of the Soviet Union from 1946 to 1953 which functioned as the country's secret police. The ministry inherited the intelligence and state security responsibilities of the People's Commissariat for Internal Affairs (NKVD) and People's Commissariat for State Security (NKGB). The MGB was led by Vsevolod Merkulov for 50 days from March 15 to May 4 1946, then by Viktor Abakumov from May 4 1946 to July 14 1951, then by Semyon Ignatiev until Stalin's death in March 5 1953, upon which it was merged into an enlarged Ministry of Internal Affairs (MVD).