Maurizio Onnis and Luca Crippa

When Germany invaded Wilhelm Brasse's native Poland in 1939, he was asked to swear allegiance to Hitler and join the Wehrmacht. He refused. He was deported to Auschwitz concentration camp as political prisoner number 3444. A trained portrait photographer, he was ordered by the SS to record the inner workings of the camp. He began by taking identification photographs of prisoners, went on to capture criminal medical experiments, and also recorded executions. Between 1940 and 1945, Brasse took around 50,000 photographs of the horror around him. He took them because he had no choice.

Eventually, Brasse's conscience wouldn't allow him to hide behind his camera. First he risked his life by joining the camp's Resistance movement. Then, when Soviet troops finally advanced on the camp to liberate it, Brasse refused SS orders to destroy his photographs. 'Because the world must know,' he said.