London-born Hardy was a Cockney who had a great talent for getting on with the people he had to photograph. In 1942 the editor of Picture Post, Tom Hopkinson, took him on after testing him on an assignment to photograph London during the Blitz. Hardy went on to cover more of the Second World War, and later, the Korean and Vietnam wars. He was among the first photographers to take pictures of the victims of the Nazi concentration camps. After Picture Post closed in 1957, Hardy worked in advertising until he finally retired in the late 1960s.