Becoming Queen, By Kate Williams

Princess Charlotte, only child of the Prince Regent, and her niece Victoria saved the Hanoverian dynasty from revolution, Kate Williams argues. People were sick of all George III's unsavoury sons, "mud from a muddy spring", as Shelley called them, and tolerated them only because Charlotte was next in line. She predeceased her father, dying in childbirth aged 21 with her baby. But Victoria's birth preserved the hope of an attractive, sober monarch. Becoming Queen considers Charlotte's life and Victoria's youth in sequence.

Each girl had a German mother humiliated by her husband's family. Each was emotionally isolated and deprived of friends; they found consolation in books and music. Each was carefully publicised, and Charlotte was spun especially well: like Victoria, she had brains, and could have made as good a constitutional ruler.

Charlotte's half begins with the story of her parents' meeting, familiar to royal biography readers. Though choosing a wife on the assumption that "one damned German frau is as good as another", the Prince Regent was shocked on meeting his bride, Caroline of Brunswick. "Harris, I am not well, pray get me a glass of brandy," were his famous first words. He recovered to father Charlotte. Her hoyden's spirits survived her parents' ill-treatment; she had 18 months of reasonably happy marriage.

Williams is funniest on the Royal Dukes, Charlotte's muddy uncles. Within days of her death, they were courting foreign princesses, within months galvanising themselves into respectable marital sex to provide a future king or queen. Kent was the winner in the ducal sperm warfare, though he died soon afterwards. His daughter Victoria was born a year after Charlotte's death.

Victoria's half of the book also draws on familiar material. "We have a vision of her as dreary and stolid," Williams claims. Surely we don't. Many books and some films have already established her as a sexy, volatile young woman. But Williams is detailed and sympathetic on the pressures of her minority. Her anxious mother and an ambitious advisor, Sir John Conroy, tried to control her like a child. In an apparently long-planned coup, she threw off their authority on the first day of her reign.

Williams conveys the pathos of hopeful European princesses and their attendants trapped inside loony protocols. She remembers the hungry world outside, of the Captain Swing and Peterloo riots. But despite the verbal liveliness of this one, another beautifully-illustrated, unsurprising royal history feels by now like a dead genre walking. It would be good to see Williams's humour and narrative talent directed to a fresh subject.