1. The SD (Sicherheitsdienst or SecurityForce) was formed by Himmler in 1931 as a security force for the Nazi party to monitor its opponents.
2. The SD were uniformed political police who kept a detailed card index of all suspected opponents of the Nazi regime at Nazi Party headquarters in Munich. It was led by Himmler’s deputy, ReinhardHeydrich.
3. As Himmler’s power grew, so did his rivalry with Heydrich, and the SD was increasingly sidelined.