Historians usually characterize the Battle of Britain as a great contest between the Luftwaffe and RAF Fighter Command that lasted from early July 1940 through to the massive daylight bombing of London during the first two weeks of September. The RAF is slightly more generous in placing the dates for the battle as occurring between 10 July and 31 October 1940. But the long and short of it is that the historical focus has emphasized the daylight, air-to-air struggle that took place over the course of three months – July, August, and September of 1940 – and not the fact that German efforts to knock Britain out of the war persisted through to spring 1941. The Battle of Britain from the perspective of those who fought it did not end until the Germans invaded the Soviet Union in late June 1941.

This chapter aims at examining adaptation over a wider space of time from early June 1940 through to the end of May 1941, when the Wehrmacht turned to conduct Operation Barbarossa, the invasion of the Soviet Union, and what Luftwaffe's chief of staff termed “a proper war.” It also aims at examining adaptation on both sides in the areas of technology, intelligence, operations, and tactics, rather than simply the contest between British fighters and German bombers and fighters – although the latter is obviously of considerable importance. Moreover, it also examines the questions surrounding the larger strategic issues of German efforts to besiege the British Isles over the course of 1940 and the first half of 1941.