The Turn of the Tide is build around the personal diaries of Field Marshal Lord Alanbrooke, who was Chief of the Imerperial General Staff and Churchill's closest military advisor. The author, Sir Arthur Bryant, terms Lord Alanbrooke's diaries "the most important of all contemporary personal records of the war". Extensive excerpts from the diaries are woven into the text together with comments on the diaries made by Lord Alanbrooke after the war.