A total number of 17 police battalions were deployed by the Orpo during the invasion of Poland in 1939. Battalion 101 was one of three from the city of Hamburg. After a few months of active duty the battalion was transported from Kielce, Poland, back to Germany on 17 December 1939 to undergo a major expansion after Christmas. Servicemen were tasked with organizing additional ground units. The already enlarged battalion was deployed to Poland again in May 1940, and for the next five months, conducted mass expulsions of Poles to make room for the German colonists brought in "Heim ins Reich" from the areas invaded by their Moscow ally as well as from the Third Reich.