Joseph Stalin made use of photo retouching for propaganda purposes. On May 5, 1920 his predecessor Vladimir Lenin held a speech for Soviet troops that Leon Trotsky attended. Stalin had Trotsky retouched out of a photograph showing Trotsky in attendance. In a well known case of "damnatio memoriae" ("condemnation of memory") image manipulation, NKVD leader Nikolai Yezhov, after his execution in 1940, was removed from an official press photo where he was pictured with Stalin; historians subsequently nicknaming him the "Vanishing Commissar". Such censorship of images in the Soviet Union was common.