The Gestapo (; abbreviation of Geheime Staatspolizei, "Secret State Police") was the official secret police of Nazi Germany and German-occupied Europe. Hermann Göring formed the unit in 1933. Beginning on 20 April 1934, it was under the administration of SS national leader, Heinrich Himmler who in 1936 was appointed Chief of German Police (Chef der Deutschen Polizei) by Hitler. In 1936, Himmler made it a suboffice of the Sicherheitspolizei (SiPo) ("Security Police"). Then from 27 September 1939 forward, it was administered by the Reichssicherheitshauptamt (RSHA) ("Reich Main Security Office") and was considered a sister organization of the Sicherheitsdienst (SD) ("Security Service"). According to historian Rupert Butler, "From its creation in 1933 until its death in May 1945, anyone living in Nazi controlled territory lived in fear of a visit from the Gestapo...".