As the Allies prepared for the liberation of Europe, the mass deportations began at a rate of four trains a day from Hungary to Auschwitz, each train carrying around 3,000 people. Between 15 May and 8 July 1944, 437,402 Hungarian Jews are recorded as having been sent there on 147 trains, most gassed on arrival. The transports comprised most of the Jewish population outside Budapest, the Hungarian capital.