Bristol Blenheim MK.IF The purpose of this volume is to provide a comprehensive detailed study of the operational and combat operations of the RAF’s Bristol Blenheim MK.IF twin-engine long-range fighter aircraft from the start of World War II in September 1939 through the battles of May and June 1940 following the German invasion of France and the Low Countries. The volume covers Fighter Commands day fighter sweeps and day/night fighter operations against enemy bombers on both sides of the English Channel including operations over Dunkirk in the latter part of May and early June. Although primarily aimed at covering Fighter Command MK.IF operations, some Coastal Command MK.IF and Blenheim MK.IVF combats with enemy aircraft are also detailed when appropriate. A brief description of the genesis and development of the Bristol Blenheim is laid down, but the volume is not designed to be a comprehensive monograph on that subject. The volume is copiously supported by a wealth of operational documents including Squadron Narratives, Group Intelligence Combat Reports, Squadron operational Records and pilot Personal Combat Reports, many of which are reproduced verbatim. Operational documents have been tied up against German reports whenever possible.