At the outset of the Second World War, John Colville, a young diplomat, was seconded from the foreign office to Number 10 Downing Street. For nine of the next sixteen years, he served three prime ministers - briefly Neville Chamberlain and Clement Attlee - but for much of that time as Private Secretary to Winston Churchill. During those momentous years Colville kept a diary, though this was forbidden by wartime regulations, locking it nightly into his desk at Number 10. Colville seldom left Churchill's side and the insights and observations he records paint an invaluable portrait of the nation's most famous leader both in times of war and peace. Transcribed and edited by Colville before his death, this new edition restores previously excised material, both from the war period and from the time when he was private secretary to the then Princess Elizabeth when she became engaged and then married Prince Philip.