After the invasion of Poland in September 1939, Hitler ordered that the Polish leadership and intelligentsia should be destroyed. The "Sonderfahndungsbuch Polen" (Special Prosecution Book Poland)—lists of people to be killed—had been drawn up by the SS as early as May 1939. The "Einsatzgruppen" (special task forces) performed these murders with the support of the "Volksdeutscher Selbstschutz" (Germanic Self-Protection Group), a paramilitary group consisting of ethnic Germans living in Poland. Members of the SS, the Wehrmacht (German Armed Forces), and the "Ordnungspolizei" (Order Police; Orpo) also shot civilians during the Polish campaign. Approximately 65,000 civilians were killed by the end of 1939. In addition to leaders of Polish society, they killed Jews, prostitutes, Romani people, and the mentally ill.