It is surprising to find Philip Ziegler writing a theatrical biography. His background is in heavyweight (well, middleweight, anyway) political biography – Mountbatten, Edward VIII, Harold Wilson, Edward Heath. I have always found him to be too reverential and pro-Establishment, so I did not have high expectations when I picked up this book. However, Ziegler has not only surprised but confounded me. He writes with economy, lucidity and directness, and his enthusiasm for the subject is positively youthful; this volume could have been written by a man in his thirties, yet Ziegler is in his eighties. Hats off, then.