• "An exemplary biography... it is full of perceptive intimacies and plenty of tradecraft, subterfuge, deception and revelation. I cannot think of a better biography of a spy chief."

    Richard Davenport-Hines, The Spectator
  • "a frank and clear-eyed, if affectionate, biography of a great public servant, cruelly traduced"

    Matthew Parris, Spectator, Books of the Year 2016
  • "An intriguing portrait of a brilliant man"

    Mail on Sunday
  • "Gripping and candid."

    The Times
  • "A welcome biography of a man able to combine warm family and personal relationships with hard-headed intellectual analysis, taking the cold decisions needed to succeed in the most unaccountable and secret of government agencies."

    Richard Norton-Taylor, Guardian