This chapter explores how the outbreak of the Second World War initiated a new and tragic period in the history of the Jews of north-eastern Europe. The Polish defeat by Nazi Germany in the unequal campaign that began in September of 1939 led to a new partition of the country by Germany and the Soviet Union. Though Hitler had been relatively slow to put the more extreme aspects of Nazi antisemitism into practice, by the time the war broke out, the Nazi regime was set in its deep-seated hatred of the Jews. Following the brutal violence of Kristallnacht on November 9–10, 1938, when up to a hundred Jews were murdered in Germany and Austria and over 400 synagogues burnt down, Hitler, disconcerted by the domestic and foreign unease which this provoked, decided to entrust policy on the Jews to the ideologues of the SS. They were determined at this stage to enforce a ‘total separation’ between Jews and Germans, but wanted to do so in an ‘orderly and disciplined’ manner, perhaps by compelling most Jews to emigrate. The Nazis did not act immediately on the genocidal threat of ‘the annihilation of the Jews as a race in Europe’, but during the first months of the war, a dual process took place: the barbarization of Nazi policy generally and a hardening of policy towards Jews.