The battalions guarded Polish prisoners of war and carried out expulsion of Poles from Reichsgau Wartheland under the banner of Lebensraum.[2] They also committed atrocities against both the Catholic and the Jewish populations as part of those "resettlement actions".[3] 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).[4]