Keeping Up with the WindsorsPrinces at War:The Bitter Battle Inside Britain's Royal Family in the Darkest Days of WWIIby Deborah CadburyPublic Affairs, 2015The old king died in 1936, and his tiny playboy eldest son came to the throne. George V was dead, and his son David, who would take the name King Edward VIII, was all set to take the throne of England – and to share it with a woman named Wallis Simpson, with whom he was hopelessly besotted even though she, as the international press was soon to repeat with gleeful repetition, “had two husbands still living.”The new king cared nothing for such matters; he expected this slightly leathery excrescence of the Baltimore demimonde to become Queen of England and Empress of India, and when his Prime Minister Stanley Baldwin, his Archbishop of Canterbury Cosmo Lang, and the heads of all the countries in Britain's sprawling Commonwealth clearly told him that such a thing could never be, that he must choose between his duty and Mrs. Simpson, he chose Mrs. Simpson. His abdication came before his coronation – and his shy, stammering brother Albert, the Duke of York, was suddenly faced with a kingship he'd been certain his whole life he could avoid.These two Royals – and their younger brothers, Prince Henry, the Duke of Gloucester, and Prince George, the Duke of Kent – are the subject of Deborah Cadbury's new book Princes at War, a gossipy and somewhat slight run-through of the various wartime fates of the Windsor princes. We get the intensely familiar stories of the two oldest boys, from the Duke of York's stutter problems and subsequent appointments with Australian speech therapist Lionel Logue (immortalized in the movie The King's Speech), and we get the usual litanies of louche David's cavalier attitude toward the hard work of being a modern constitutional British monarch:

Edward VIII had appeared to approach the role of king like a spoiled child at a party: the presents were all magnificent but they were the wrong ones. His laziness and unwillingness to co-operate was widely rumoured in court circles. Documents of State were returned unread. Representatives of august institutions as diverse as the Quaker Society of Friends and the Bank of England were instructed that they must address the king together. He offended the Church by his failure to attend services regularly or take communion on Sundays.

The book is at its strongest when covering ground perhaps less familiar to its readers, the personalities and wartime service of the two younger brothers. Like everybody who met him, Cadbury seems all but enchanted with the Duke of Kent, whom she refers to as “hedonistic and glamorous,” possessed of “film star good looks and champagne charisma,” and whom she describes as “a princely playboy to whose irresistible good looks a series of women, possibly men too, had surrendered.” (If you blinked a little at one part of that last description, don't worry: you didn't misread it. There are whole books about the Duke of Kent that will never be written). Kent became an honorary air commodore in the RAF and died in 1942 when his air transport crashed into a mountain in Scotland – the first member of the Royal Family to die in military service in centuries.About the remaining brother, the Duke of Gloucester, Cadbury is perhaps too tough-minded. This affable gentleman, who saw active rather than ceremonial service during WWII and lived until 1974, was neither as charismatic as Kent nor as intelligent as York nor as glib as Prince David, and he tends to take it on the chin in the course of Cadbury's narrative:

Like his father he had a keen interest in ceremonial occasions and was conscientious about details of dress and uniform, but he did not appear to be blessed with many other skills so badly needed for life in the public eye. Gloucester was often cast as the least intelligent of the brothers, who wanted nothing more than a quiet life in the army. It was well known he was most at ease in the company of his drinking friends and that their escapades were at times excessive. Yet this was the man who was about to be elevated to the next adult in line for the throne.

But the bulk of Princes at War is devoted to the two kings – one on the throne, one in a voluntary exile as Governor of the Bahamas under the new title of Duke of Windsor. King George VI's steadfast devotion to his duty is contrasted with the Duke of Windsor's sullen rancor and rumored back-channel sympathies for the very Nazi powers his younger brother was fighting so desperately half a world away.As noted, it's familiar ground, and the execution here is saved from tedium only by Cadbury's effervescence as a storyteller. Completist Windsor-watchers will want to add this book to the season's surprisingly health roster of must-buy titles, alongside Andrew Morton's uproarious 17 Carnations and Catherine Mayer's thoroughly excellent Charles: The Heart of a King.