Höss joined the Nazi party in November 1922, shortly after it was founded. Heinrich Himmler, an ardent Nazi talent spotter who knew Höss from the early days, invited him to become an active member of the SS. Höss accepted and in November 1934 arrived at Dachau concentration camp in Bavaria to start his service as a guard. Dachau in the 1930s was not a place of mass extermination. The majority of prisoners sent there were released after a stay of imprisonment of around a year to eighteen months. Intense mental and physical suffering were inflicted on the prisoners, many of whom died, but it was easy for Höss to rationalise. He felt it was important to imprison and forcibly 're-educate' the internal opponents of the Third Reich. Höss's three-and-a-half years at Dachau were to play a defining role in shaping his mentality. Above all else, it is where Höss learnt the essential philosophy of the SS, as preached by Theodor Eicke, the first commandant of the camp - hardness: "Anyone who shows even the slightest vestige of sympathy towards [the prisoners] must immediately vanish from our ranks. I need only hard, totally committed SS men. There is no place among us for soft people." Rudolf Hoess on the right; with Heinrich Himmler. Höss was a model SS man and rose through the ranks, eventually being promoted to Rapportfuehrer, chief assistant to the commander of Dachau. In September 1936 he was made a lieutenant and transferred to Sachsenhausen concentration camp, where he remained until his elevation to commandant of the new concentration camp at Auschwitz. This then was the man who arrived at Auschwitz in May 1940. He now felt ready to take on his biggest challenge, creating a new concentration camp from a handful of vermin infested barracks. His experience at Dachau and Sachsenhausen offered a clear blueprint. During his first year at the camp, Höss oversaw the expansion of Auschwitz from a poorly-resourced but brutal concentration camp for Poles into a source of slave labour for the construction of the giant synthetic oil and rubber factory at nearby Monowitz. It was also readied for the arrival of selected Soviet prisoners of war in July 1941. It was to murder these "sub-human" Soviet prisoners, as well as to kill those considered 'unfit' to work, that Zyklon B was first used at Auschwitz. It was Höss's deputy, Karl Fritzch, who first thought of using the readily available insecticide to kill human beings. Höss records that he personally attended an early gassing experiment: "Protected by a gas mask, I watched the killing myself. In the crowded cells death came instantaneously the moment the Zyklon B was thrown in. A short, almost smothered cry and it was all over." While the evidence is that death could be far from "instantaneous", Höss was nonetheless "relieved" that this new method of killing had been found so he would be spared a bloodbath. He saw his subordinate's innovation as an "improvement" a method of murder that would cause less psychological damage to his men than killing by firing squad. At Auschwitz-Birkenau, a new camp being built two miles away from the main camp, Höss oversaw the conversion of two cottages into makeshift gas chambers. By 1943, a total of four purpose-built crematoria with attached gas chambers had been completed. These killing installations would eventually contribute to the physical destruction of one million, one hundred thousand people, a million of whom were Jews. Höss's long career in concentration camps prepared him step-by-step for the moment when the gassings began at Auschwitz, thereby allowing him carry on, calmly and faithfully, organising the killing. He was never faced with one sudden, stark command that he should commit mass murder. Höss lived with his wife and four children in a house just yards from the crematorium in Auschwitz main camp, where some of the earliest killing experiments were conducted using the poisonous insecticide Zyklon B. During his working days, Höss presided over the murder of more than a million people, but once he came home he lived the life of a solid, middle-class German husband and father.