Sir Alexander Cadogan was one of the most outstanding civil servants Britain has ever known. He kept a diary from 1933 until the year of his death, 1968, at the age of eighty-three. This volume concentrates on the crucial years from 1938 to 1945. In 1938 Sir Alexander became the Under-Secretary of State at the Foreign Office. He was to hold that position for the next eight years.

As chief adviser to three Foreign Secretaries, Eden (for two periods), Halifax and Bevin, working under three Prime Ministers in Chamberlain, Churchill and Attlee, Cadogan had longer consecutive service at the centre of British affairs than any of them. His tenure of office lasted from the first rumblings of the Czechoslovak and Munich crises through the entire war years to the establishment of the United Nations Organization (in the birth of which - and later as Britain''s Permanent Representative - he had a profound and formative role admired on both sides of the Iron Curtain).

As head of the Foreign Office, trusted and respected by statesmen and colleagues alike for his calm courage, integrity and ''common sense and judgement carried to the point where they almost amounted to genius'', Cadogan played a vital part in the conduct and decision-making if his country''s affairs. For eight years he attended the most important Cabinet and Cabinet Committee meetings, ran a great Department of State, and accompanied Churchill on his many wartime journeys to the Big Power conferences at Washington, Moscow, Cairo, Tehran and Yalta.

Sir Alexander''s meticulously kept private record of those years is a document of the highest historical value. It illumines the workings of the Foreign Office and the Cabinet, the conduct of alliances and international diplomacy at a time of unparalleled importance. From these diaries and the more personal ''diary letters'' sent by Sir Alexander to his wife when he travelled abroad, David Dilks has produced a book of lasting importance.

On 15 August 1945, with the announcement of the Japanese surrender, Cadogan wrote: '' . . . here is the culmination. The problems in front of us are manifold and awful. But I''ve lived through England''s finest hour . . . '' In essence, The Diaries of Sir Alexander Cadogan are a record of the part played in that hour by one of England''s finest servants.