The Einsatzgruppen were formed under the direction of SS-Obergruppenführer Reinhard Heydrich and operated by the Schutzstaffel (SS) before and during World War II.[4] The Einsatzgruppen had their origins in the ad hoc Einsatzkommando formed by Heydrich to secure government buildings and documents following the Anschluss in Austria in March 1938.[5] Originally part of the Sicherheitspolizei (Security Police; SiPo), two units of Einsatzgruppen were stationed in the Sudetenland in October 1938.