The Cheka was the secret police of the Bolsheviks, existing from 20 December 1917 to 6 February 1922. Hundreds of Cheka committees were created in various cities across Russia and the former Russian Empire, and the cheka executed, arrested, or tortured thousands of dissidents, deserters, and other enemies of the Bolsheviks during the Russian Revolution and the Russian Civil War. In 1922, the Cheka was reorganized into the NKVD with the establishment of the Soviet Union.