In this the most important volume of the great biographical enterprise in which he has been involved for twenty years, Martin Gilbert probes beneath the surface of each of the crucial decisions in which Churchill was involved from the outbreak of war in September 1939 to the Japanese attack on Pearl Harbour in December 1941. In a powerfully documented account he reveals not only how each decision was reached, but precisely what influences lay behind it, whether of individuals, or of information reaching Churchill from the most secret source of British Intelligence. Drawing on a remarkable diversity of material, including the War Cabinet and other Government records, as well as Churchill's own vast archive of private letters, and piecing together the documents Churchill received and sent with the diaries and letters of his private secretariat and the recollections of those who worked with him at the moments of greatest crisis, Martin Gilbert reveals for the first time the full extent of Churchill's personal contribution to every aspect of the struggle. It was one of Churchill's inner circle who said to the author: 'We who worked with Churchill every day of the war still saw at most a quarter of his daily task and worries.' Martin Gilbert has pieced together the whole, setting in their context many thousand documents, as well as diary comments and other hitherto scattered and secret evidence, in order to give the fullest, most intimate and most fascinating historical account yet published of the architect of Britain's 'finest hour'.