Nikolai Ivanovich Yezhov was a Soviet secret police official under Joseph Stalin who was head of the NKVD from 1936 to 1938, during the height of the Great Purge. Yezhov organized mass arrests, torture and executions during the Great Purge, but he fell from Stalin's favour and was arrested, subsequently admitting in a confession to a range of anti-Soviet activity including "unfounded arrests" during the Purge. He was executed in 1940 along with others who were blamed for the Purge.

Genrikh Grigoryevich Yagoda was a Soviet secret police official who served as director of the NKVD, the Soviet Union's security and intelligence agency, from 1934 to 1936. Appointed by Joseph Stalin, Yagoda supervised arrests, show trials, and executions of the Old Bolsheviks Lev Kamenev and Grigory Zinoviev, climactic events of the Great Purge. Yagoda also supervised construction of the White Sea–Baltic Canal with Naftaly Frenkel, using penal labor from the gulag system, during which 12,000–25,000 laborers died.