[2] With the formation of the RSHA, Himmler combined under one roof the Nazi Party's Sicherheitsdienst (SD; SS intelligence service) and the Sicherheitspolizei (SiPo; "Security Police"), which was nominally under the Interior Ministry.

[3] In correspondence, the RSHA was often abbreviated to RSi-H[4] to avoid confusion with the SS-Rasse- und Siedlungshauptamt (RuSHA; "SS Race and Settlement Office").

Departments like the SD and Gestapo (within the RSHA) were controlled directly by Himmler and his immediate subordinate SS-Obergruppenführer and General of Police Reinhard Heydrich; the two held the power of life and death for nearly every German and were essentially above the law.

In January 1943 Himmler delegated the office to SS-Obergruppenführer and General of Police Ernst Kaltenbrunner, who headed the RSHA until the end of the war in Europe.

"The complexity of RSHA was unequalled... with at least a hundred... sub-sub-sections, a modest camouflage of the fact that it handled the progressive extermination which Hitler planned for the ten million Jews of Europe".

[13] The organization at its simplest was divided into seven offices (Ämter):[14][15] RSHA-controlled activities included gathering intelligence, criminal investigation, overseeing foreigners, monitoring public opinion, and Nazi indoctrination.

[28] Entry into the Second World War afforded the RSHA the power to act as an intermediary in conquered or occupied territories, which according to Hans Mommsen, lent itself to implementing the extermination of Jewish populations in those places.

[30] Part of the RSHA's efforts to encourage occupied nations to hand over their Jews included coercing them by assigning Jewish advisory officials.

When the units were re-formed prior to the invasion of the Soviet Union in 1941, the men of the Einsatzgruppen were recruited from the SD, Gestapo, Kripo, Orpo, and Waffen-SS.

[37] As early as 1941, Propaganda Minister Joseph Goebbels began to complain that large numbers of Jews had not been transported out of Germany because of their work in the armaments industry.

[47] On 8 March, RSHA head Ernst Kaltenbrunner told Interior Minister Wilhelm Frick that the deportations had been limited to Jews who were not intermarried.