Order Police battalions were militarised formations of the German Order Police ( uniformed police ) during the Nazi era . During World War II , they were subordinated to the SS and deployed in German-occupied areas , specifically the Army Group Rear Areas and territories under German civilian administration . Alongside detachments from the '' Einsatzgruppen '' and the Waffen-SS , these units perpetrated mass murder of the Jewish population and were responsible for large-scale crimes against humanity targeting civilian populations . The German Order Police was a key instrument of the security apparatus of Nazi Germany . In the prewar period , Heinrich Himmler , the head of the SS , and Kurt Daluege , chief of the Order Police , cooperated in transforming the police force of the Weimar Republic into militarised formations ready to serve the regime 's aims of conquest and racial annihilation . The police units participated in the annexation of Austria and the occupation of Czechoslovakia . Police troops were first formed into battalion-sized formations for the invasion of Poland , where they were deployed for security and policing purposes , also taking part in executions and mass deportations . The first 17 battalion formations were deployed by Orpo in September 1939 along with the Wehrmacht army in the invasion of Poland . The battalions guarded Polish prisoners of war and carried out expulsion of Poles from '' Reichsgau Wartheland '' under the banner of '' Lebensraum '' . They also committed atrocities against both the Catholic and the Jewish populations as part of those " resettlement actions " . After hostilities had ceased , the battalions − such as Reserve Police Battalion 101 − took up the role of security forces , patrolling the perimeters of the Jewish ghettos in German-occupied Poland ( the internal ghetto security issues were managed by the SS , SD , and the Criminal Police , in conjunction with the Jewish ghetto administration )
expulsion of Poles
Expulsion of Poles by Nazi Germany
Order Police battalions