Before the German-Soviet invasion of 1939, Kraków (Cracow) was an influential centre for the 60,000–80,000 Polish Jews who had lived there since the 13th century. Persecution of the Jewish population of Kraków began immediately after the German troops entered the city on 6 September 1939 in the course of the invasion. Jews were ordered to report for forced labour beginning in September 1939. In November, all Jews twelve years or older were required to wear identifying armbands. Throughout Kraków, synagogues were closed and all their relics and valuables confiscated by the Nazi authoritiesBy May 1940, the Nazi occupation authority under Gauleiter Hans Frank announced that Kraków should become the "racially cleanest" city in the General Government (an occupied, but unannexed part of Poland). Massive deportations of Jews from the city were ordered. Of the more than 68,000 Jews in Kraków when the Germans invaded, only 15,000 workers and their families were permitted to remain. All other Jews were ordered out of the city, to be resettled into surrounding rural areas of the Generalgouvernement.