Brown highlights one utterly discreditable episode in the queen’s life, in which she sacked her racing trainer, and evicted him from a house she owned — when he was undergoing heart surgery and had not long before broken his neck. This incomprehensible decision was intensely unpopular, and was generally attributed to the malign influence of her crony Lord Carnarvon, to whom she seemed nearly as close as to the Duke of Edinburgh, her cantankerous consort.

The “annus horribilis,” as the queen called it, of 1992 saw marital breakups of the Prince and Princess of Wales and the Duke and Duchess of York, along with attendant scandals. Prince Philip was chancellor of Cambridge University. That year an honorary degree was conferred on Jacques Derrida, and when somebody described him as the exponent of deconstruction theory, Brown relates, Prince Philip was overheard muttering that his own family seemed to be deconstructing pretty well.

Even if Queen Elizabeth remains a mystery, and if some of the mawkish devotion once showered on her was cloying, perhaps this isn’t a bad time to recognize the virtues of constitutional monarchy, with a head of state selected randomly by inheritance who can be respected by the public and stands above the strife and sometimes squalor of politics.

Over the years American friends have asked me in a slightly condescending way, “Would you really rather have Queen Elizabeth as your head of state than” whatever president was in power at the moment? — be it Richard Nixon, Bill Clinton or George W. Bush — to which I would reply, “Since you ask, yes, actually.”

Funnily enough, no one has asked me this recently.

QUEEN VICTORIA AND HER PRIME MINISTERS: Her Life, the Imperial Ideal, and the Politics and Turmoil That Shaped Her Extraordinary Reign | By Anne Somerset | Knopf | 630 pp. | $45

Q: A Voyage Around the Queen | By Craig Brown | Farrar, Straus & Giroux | 664 pp. | $35