The Committee for State Security (CSS) (Komitet gosudarstvennoy bezopasnosti (KGB), kəmjɪˈtjet ɡəsʊˈdarstvjɪn(ː)əj bjɪzɐˈpasnəsjtjɪ) was the main security agency for the Soviet Union from 13 March 1954 until 3 December 1991. As a direct successor of preceding agencies such as the Cheka, GPU, OGPU, NKGB, NKVD and MGB, it was attached to the Council of Ministers. It was the chief government agency of "union-republican jurisdiction", carrying out internal security, foreign intelligence, counter-intelligence and secret police functions. Similar agencies operated in each of the republics of the Soviet Union aside from the Russian SFSR, where the KGB was headquartered, with many associated ministries, state committees and state commissions.
The agency was a military service governed by army laws and regulations, in the same fashion as the Soviet Army or the MVD Internal Troops. While most of the KGB archives remain classified, two online documentary sources are available. Its main functions were foreign intelligence, counter-intelligence, operative-investigative activities, guarding the state border of the USSR, guarding the leadership of the Central Committee of the Communist Party and the Soviet Government, organization and security of government communications as well as combating nationalist, dissident, religious and anti-Soviet activities.
On 3 December 1991, the KGB was officially dissolved. It was later succeeded in Russia by the Foreign Intelligence Service (SVR) and what would later become the Federal Security Service (FSB). Following the 1991–1992 South Ossetia War, the self-proclaimed Republic of South Ossetia established its own KGB, keeping the unreformed name. In addition, Belarus established its successor to the KGB of the Byelorussian SSR in 1991, the Belarusian KGB, keeping the unreformed name.
ChekaOGPUNKGB and Ministry for State Security (Soviet Union)Restructuring in the MVD following the fall of Beria in June 1953 resulted in the formation of the KGB under Ivan Serov in March 1954.