Robin Butler, Lord Butler of Brockwell, joined the civil service in 1961, retiring as Cabinet Secretary thirty-six years later. During his remarkable career, he served as Private Secretary to Edward Heath, Harold Wilson and Margaret Thatcher and as Cabinet Secretary under Thatcher, John Major and Tony Blair. He was also head of the Home Civil Service between 1987 and 1997, and is, perhaps, best known to the general public as the chairman of the 2004 inquiry into Iraq's weapons of mass destruction. In this illuminating political biography Michael Jago cleverly weaves a narrative around Robin Butler's remarkable career as a civil servant, measured against the changing background of British politics over the past forty years. It is significant that at the dinner to celebrate his retirement from the civil service in 1997, his guests included Lady Wilson of Rievaulx, widow of Harold Wilson, Prime Minister for the first time in 1964; Cabinet ministers from subsequent governments through to members of the Labour Cabinet that came to power in 1997.During those thirty-six years, Butler successfully preserved the traditions of the Civil Service - above all, political impartiality - while implementing far-reaching changes and more mobility between the service and the outside world. It is that pivotal role, examined while the paint is still fresh, that is the subject of this biography.