A Voyage Around the Queen by Craig Brown
Craig Brown’s unconventional biography of Queen Elizabeth II was a disappointment. By all accounts, QEII never said (publicly at least) anything interesting, and her only real passions were horses and corgis. Her legendary discretion, stamina, and sense of duty were admirable, but don’t make for gossipy reading.
The subject of Brown’s previous Royal, Princess Margaret, was notoriously indiscrete which makes Ninety-Nine Glimpses of Princess Margaret a lot more fun. I recommend it.
See also the QE II mystery novels by S.J. Bennett.