The Committee for State Security, more commonly known by its transliteration “KGB” Komitet gosudarstvennoy bezopasnosti (KGB), was the main security agency for the Soviet Union from 1954 until its collapse in 1991. The committee was a direct successor of such preceding agencies as Cheka, NKGB, and MGB. It was the chief government agency of “union-republican jurisdiction”, acting as internal security, intelligence, and secret police. Similar agencies were instated in each of the republics of the Soviet Union aside from the Russian SFSR and consisted of many ministries, state committees and state commissions.
The KGB also has been considered a military service and was governed by army laws and regulations, similar to the Soviet Army or MVD Internal Troops. While most of the KGB archives remain classified, two on-line documentary sources are available.Its main functions were foreign intelligence, counterintelligence, operative-investigatory activities, guarding the State Border of the USSR, guarding the leadership of the Central Committee of the Communist Party of the Soviet Union and the Soviet Government, organization and ensuring of government communications as well as fight against nationalism, dissent, and anti-Soviet activities.