The Sicherheitspolizei (), often abbreviated as SiPo, was a term used in Germany for security police. In the Nazi era, it referred to the state political and criminal investigation security agencies. It was made up by the combined forces of the Gestapo (secret state police) and the Kriminalpolizei (criminal police; Kripo) between 1936 and 1939. As a formal agency, the SiPo was incorporated into the Reich Security Main Office (RSHA) in 1939, but the term continued to be used informally until the end of World War II in Europe. Origins The term originated in August 1919 when the Reichswehr set up the Sicherheitswehr as a militarised police force to take action during times of riots or strikes. Owing to limitations in army numbers, it was renamed the Sicherheitspolizei to avoid attention. They wore a green uniform, and were sometimes called the "Green Police". It was a military body, recruiting largely from the Freikorps, with NCOs and officers from the old German Imperial Army. Nazi era When the Nazis came to national power in 1933, Germany, as a federal state, had myriad local and centralized police agencies, which often were un-coordinated and had overlapping jurisdictions. Heinrich Himmler and Reinhard Heydrich's plan was to fully absorb all the police and security apparatus into the structure of the Schutzstaffel (SS). To this end, Himmler took command first of the Gestapo (itself developed from the Prussian Secret Police). Then on 17 June 1936 all police forces throughout Germany were united, following Adolf Hitler's appointment of Himmler as Chef der Deutschen Polizei (Chief of German Police). As such he was nominally subordinate to Interior Minister Wilhelm Frick, but in practice Himmler answered only to Hitler. Himmler immediately reorganised the police, with the state agencies statutorily divided into two groups: the Ordnungspolizei (Order Police; Orpo), consisting of both the national uniformed police and the municipal police, and the Sicherheitspolizei (Security Police; SiPo), consisting of the Kripo and Gestapo. Heydrich was appointed chief of the SiPo and was already head of the party Sicherheitsdienst (Security Service; SD) and the Gestapo. The two police branches were commonly known as the Orpo and SiPo (Kripo and Gestapo combined), respectively. The idea was to fully identify and integrate the party agency (SD) with the state agency (SiPo). Most of the SiPo members were encouraged or volunteered to become members of the SS and many held a rank in both organisations.