In March 1953 Lavrentii Beria united the MVD and MGB into one body, the MVD. Within a year Beria's execution caused the MVD to be split up. The reformed MVD retained its internal security functions while the new KGB took on state security functions. The KGB was subordinated to the Council of Ministers. On 5 July 1978 the KGB was renamed the "KGB of the USSR" with the KGB Chairman given a seat on the council.
It's tasks were external espionage, counter-espionage, liquidation of anti-Soviet and counter-revolutionary formations in the USSR and guarding the leaders of the party and state.
The KGB was organized into directorates, some of the main directorates were:
First Chief Directorate (Foreign Operations) was responsible for foreign operations and intelligence-gathering activities.
The Second Chief Directorate was responsible for internal political control of citizens and foreigners within the Soviet Union.
Third Chief Directorate (Armed Forces) controlled military counterintelligence and political surveillance of the armed forces.
Fifth Chief Directorate also dealt with internal security. Created to combat political dissent, it took up some of the tasks previously handled by the Second Chief Directorate.
Seventh Directorate (Surveillance) handled surveillance, providing equipment to follow and monitor the activities of both foreigners and Soviet citizens.
Eighth Chief Directorate was responsible for communications. It dealt with monitoring foreign communications and was also responsible for the cryptological systems used by KGB divisions, transmission to KGB stations overseas, and the development of communication equipment
Ninth Directorate (Guards Directorate) provided guards for principal Party leaders and their families, and major government facilities in the Soviet Union.
The KGB was dissolved due to the participation of its chief, Colonel General Vladimir Kryuchkov, in the August 1991 coup attempt. He used many of the KGB's resources to aid the coup attempt. Kryuchkov was arrested after the conclusion of the coup attempt and General Vadim Bakatin was appointed Chairman on 23 August 1991 with a mandate to dismantle it. On 6 November 1991 the KGB officially ceased to exist.
Heads of the KGB or equivalent
OGPU merged into the NKVD in July 1934
Ministry of State Security (MGB)
Vsevolod Nikolayevich Merkulov March 19 1946 - May 7 1946
Viktor Semyonovich Abakumov May 7 1946 - July 14 1951
Sergey Ogoltsov July 14 1951 - August 9 1951
Semyon Denisovich Ignatiyev August 9 1951 - March 5 1953
Committee for State Security (KGB)
Ivan Aleksandrovich Serov March 13 1954 - December 8 1958
Aleksandr Nikolayevich Shelepin December 25 1958 - November 13 1961
Vladimir Yefimovich Semichastniy November 13 1961 - May 18 1967
Yuri Vladimirovich Andropov May 18 1967 - May 26 1982
Vitaliy Vasilyevich Fedorchuk May 26 1982 - December 17 1982
Viktor Mikhaylovich Chebrikov December 17 1982 - October 1 1988
Vladimir Aleksandrovich Kryuchkov October 1 1988 - August 22 1991
Leonid Nikolayevich Shebarshin August 22 1991 - August 23 1991 (Acting)
Vadim Viktorovich Bakatin August 23 1991 - October 22 1991