State Political Directorate was the secret police of the RSFSR and USSR until 1934. Formed from the Cheka on February 6, 1922, it was initially known under the Russian abbreviation GPU for Gosudarstvennoye Politicheskoye Upravlenie of NKVD of the RSFSR (Государственное Политическое Управление НКВД РСФСР).
With the creation of the USSR, a unified organization was required to exercise control over state security throughout the new Union. Thus, on November 15, 1923, the GPU was transformed into Joint State Political Directorate - Ob'edinennoe Gosudarstvennoe Politicheskoe Upravlenie under SNK of the USSR (Объединённое государственное политическое управление при СНК СССР), or OGPU (ОГПУ), also translated as All-Union State Political Administration.
Perhaps the most spectacular success of the GPU/OGPU was the Trust Operation, 1924-1925. GPU agents contacted emigrés in western Europe and pretended to be representatives of a large group working for the overthrow of the communist regime, known as the "Trust". Exiled Russians gave the Trust large sums of money and supplies, as did foreign intelligence agencies. The Trust finally succeeded in luring one of the leading anti-Communist operators, Sidney Reilly, into Russia to meet with the Trust. Once he was in Russia, he was captured and killed. The Trust was dissolved, and it became a large propaganda success.
The OGPU was responsible for the creation of the GULAG system. It also became the Soviet government's arm for the persecution of the Russian Orthodox Church and other religious organizations, an operation headed by Eugene Tuchkov.
OGPU was reincorporated into NKVD of the USSR in July 1934, becoming the GUGB department. Its final transformation was into the more infamously known Committee for State Security (KGB).

See also

Chronology of Soviet secret police agencies