If the revelations contained in this book about Winston Churchill’s personal finances had been common knowledge in 1940, he might not have become prime minister. For what David Lough shows in compelling detail is that the political risk-taker, who had notoriously described the disastrous Dardanelles expedition as ‘a legitimate war gamble’, was even more reckless in private than he was in his public life. No one who had been so irresponsible with his own fortune, it would surely have been said, should be entrusted with the fortunes of the nation. Luckily for the nation, its saviour kept his serial improvidence under wraps.

In his personal papers, however, Churchill retained much of the raw evidence. Some of it is already in print thanks to studies, by David Reynolds and Peter Clarke respectively, of the publishing history of Churchill’s books The Second World War and The English-Speaking Peoples. But Martin Gilbert’s official biography is