Chronology of Soviet secret police agencies to operate as well. Chronology of Soviet secret police agencies <br> 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. For most agencies listed here secret policing operations were only part of their function; for instance, the KGB was both the secret police
NKVD known as the GULag) as well as the regular police. At various times, the NKVD had the following Chief Directorates, abbreviated as "ГУ"– , . Until the reorganization begun by Nikolai Yezhov with a purge of the regional political police in the autumn of 1936 and formalized by a May 1939 directive of the All-Union NKVD by which all appointments to the local political police were controlled from the center, there was frequent tension between centralized control of local units and the collusion of those units with local and regional party elements, frequently resulting in the thwarting of Moscow's plans.