The largest and most notorious of Vernichtungslager, extermination camps. Auschwitz, some 150 miles from Warsaw, was first built as a concentration camp for Poles in May 1940 and was placed under the command of Rudolf Hoss, who had been promoted from Sachsenhausen. In October a second camp, Birkenau, was added, first for 100.000 Russian prisoners and then for Jews to be used as slave labour. In June 1941, under direct orders from Himmler, Auschwitz was greatly extended. `Bathhouses', disguised gas chambers, were added and Leichenkeller (corpse cellars) were built to house the dead before the bodies were burned in the now effective crematoria. Commandant Hoss has testified that at that time Belzek, Treblinka and Wolzek were being adapted to the purposes of mass extermination. Thus six months before the Wannsee conference (January 1942) the first practical steps in the organization of the Final Solution had already taken place. There is no doubt that from the beginning Auschwitz was assigned a leading role. Commandant Hoss was determined not to disappoint his superiors. Visiting Treblinka he was unimpressed by their killing method using carbon monoxide gas from truck or tank engines: he found the process too lengthy and too uncertain in outcome. Not without pride he claimed to have been responsible for the introduction of the considerably more efficient Zyklon-B gas system at Auschwitz. In the new gas chambers 2.000 people at a time could be accommodated, against 200 at Treblinka. In his evidence at his post-war trial Hoss then explained the process of selection by which some prisoners were diverted to work in the factory area which developed as part of the vast Auschwitz-Birkenau complex. Here IG Farben and companies like Krupp's worked their labourers until they collapsed. At the initial selection process a young and fit prisoner might win, by his or her appearance, another few months' lease of life. The others were directed to the column whose fate was to be immediate gassing. `Children of tender years,' Hoss said, `were inevitably exterminated since by reason of their youth they were unable to work.' From time to time riots occurred, but Hoss intimated that they were suppressed without difficulty. Secrecy was a more intractable problem. People in the Polish communities around Auschwitz certainly knew what was happening, Hoss conceded, `since the foul and nauseating stench of the continuous burning of bodies permeated the whole area'. Great efforts were made, however, to disguise from the incoming Jews the nature of their fate. At Birkenau the railway track - in fact in every sense the end of the line - appeared to run on at least as far as the next bend. Prisoners were informed that they were to be disinfected in the vast `bathhouses', and some were even issued with printed postcards: `We have work and are well treated. We await your arrival,' to be sent back to relatives or friends at home. The numbers murdered were colossal. Frequently no count was made. The transports arriving from all over Europe from 1942 onwards carried 6.000- 7.000 people at a time, sometimes more than once a day. The hideous suffering of the victims on journeys in crowded cattle-cars was nothing compared to the horrors on arrival at Auschwitz. On the ramp, SS doctors, of whom Mengele was just one serving officer, made the selection. If it was still difficult to believe that the purpose of their journey was extermination, no adult Jew at this point doubted that at the best only brutal mistreatment awaited them. After gassing, the bodies were cremated. At Auschwitz the numbers were, by 1944, in excess of 6.000 daily. In the summer of that year over 250.000 Hungarian Jews were murdered in six weeks. The charnel house could not handle the task. Victims who might by now be gassed or shot were thrown into ditches, covered with benzene and burnt in the open. As the pace of murder became more frenetic even Commandant Hoss, proud of his totals though he was, could no longer keep accurate count. His own figure fluctuated between 3.00.000 and 1.135.000 killed. Perhaps a million and a half human beings, mostly European Jews but also Russian prisoners of war and gypsies, died at Auschwitz.