Cheka (ЧК - чрезвыча́йная коми́ссия chrezvychaynaya komissiya, Emergency Commission, ) was the first of a succession of Soviet state security organizations. It was created on December 20, 1917, after a decree issued by Vladimir Lenin, and was subsequently led by Felix Dzerzhinsky, an aristocrat turned communist. By late 1918, hundreds of Cheka committees had been created in various cities, at multiple levels including: oblast, guberniya ("Gubcheks"), raion, uyezd, and volost Chekas, with Raion and Volost Extraordinary Commissioners. Many thousands of dissidents, deserters, or other people were arrested, tortured or executed by various Cheka groups. After 1922, Cheka groups underwent a series of reorganizations, with the NKVD, into bodies whose members continued to be referred to as "Chekis