In the spring of 1936, teenage schoolboy – and later war hero – Dick Hargreaves was offered the opportunity to go on an all-expenses-paid exchange trip to Germany. But this was no ordinary school exchange – Hargreaves’ destination was Oranienstein, one of a system of new elite boarding schools known as the National Institute of Political Education (“Napoles” for short). These Nazi colleges were clearly based on a mixture of British public schools, the Prussian cadet corps and the rigorous educational practices of ancient Sparta. The schools educated boys from the age of ten, training them to be future leaders...