The role of the BEF in the fall of France and the retreat to Dunkirk. Covering the 1939-40 'Phoney War' in a single chapter, the focus of Major L.F. Ellis's official history of the campaign in France and Flanders falls on the role of the British Expeditionary Force in attempting to defend Belgium and France from the fury of the German Blitzkrieg in May-June 1940.