Given the endless stream of books on the Second World War that appear on the bookshelves every year, I must confess that I think it might be time for historians to call an armistice. Indeed the story is so familiar that I must confess also to a sneaking sympathy for Don DeLillo’s Morehouse Professor of Latent History, a wonderful, if bizarre, character who appears in DeLillo’s 1973 novel Great Jones Street. It is axiomatic, the Professor reminds his readers, that history is the record of events. ‘But what of Latent History? We all think we know what happened. But did it really happen? Or did something else happen?’ DeLillo’s professor studies events that almost took place, events that definitely took place but went unseen, as well as events that probably took place but were not chronicled at the time. Like many of the author’s characters the Morehouse Professor is a marvellous creation of the postmodern sensibility, especially our fascination with counterfactual history.

Ian Kershaw is not a postmodern writer. His book, he tells us from the beginning, is not counterfactual or Virtual History, of the type which makes an intellectual guessing game of some distant future and projects what might have happened had some event not taken place. Kershaw is one of