Who is Feliks Edmundovich Dzerzhinsky from The Gulag Archipelago, 1918-1956 and what is their importance?

The first chief of the secret police, Dezerzhinsky inconveniently abolishes capital punishment during the "Churchmen" trial in 1920. During the first year of peace after the Civil War (1922), the Cheka's authority is narrowed and it is renamed the GPU. Dzerzhinsky tells Pravda that it has strengthened its ability to watch for "anti-Soviet currents and groupings." Lenin secretly favors deporting bourgeois intelligentsia after framing them as military spies, but when many of the émigrés regard this as a gift, Dzerzhinsky turns to using the Gulag.