For 12 long years between 1933 until 1945, the inhuman Nazi regime in Germany waged a brutal, pitiless war on groups of people whom they considered inferior. Jews, Roma, Slavs, the disabled and homosexuals, as well as political opponents and religious enemies, were among the victims of what would become known as the Holocaust.Jews, whom the Nazis believed had been the authors of their country's downfall, were particular targets. At first through discrimination and persecution but later through violence, enslavement and mass murder, Hitler's henchmen and women carried out a merciless attempt to exterminate an entire people.Mobile squads of killers roamed eastern Europe seeking out their prey. Then, in a grisly attempt to industrialise the process of genocide, the Nazis opened up their death camps. Hundreds of thousands of men, women and children passed through the gates of camps such as Auschwitz-Birkenau and Treblinka. Hundreds of thousands never came out.The first of the death camps was liberated in 1944 and the unimaginable truth of the atrocities of the Holocaust began to emerge in 1945. But it was not until the 1960s that the scale and meaning of the years of murder began to be truly appreciated in the western world.Seventy years on from the liberation, it is time to reassess one of the most infamous episodes in mankind's history.