There was a succession of Soviet secret police agencies over time. The first secret police after the October Revolution, created by Vladimir Lenin's decree on December 20, 1917, was called "Cheka" (ЧК). Officers were referred to as "chekists", a name that is still informally applied to people under the Federal Security Service of Russia, the KGB's successor in Russia after the dissolution of the Soviet Union.
February 6, 1922: Cheka transforms into GPU, a department of the NKVD of the Russian SFSR.
November 15, 1923: GPU leaves the NKVD and becomes all-union OGPU under direct control of the Council of People's Commissars of the USSR.