The Allied campaign in North-West Europe in 1944–45 ended with the capitulation of the German Army and must, therefore, be considered an eminently successful operation. In its initial phase, that is the assault on Normandy and the securing of a defensible lodgement area, it was undoubtedly one of the most dangerous and complicated operations of the war. Nevertheless it ended as the victory which marked the beginning of the end of the Third Reich. Like many other campaigns, however, it did not go exactly as planned and many have claimed that the Allied Armies were neither properly trained nor adequately led and that, therefore, some other element ensured the victory. The overwhelming power of the Allied air force and its effects on the operations of the German Army has been the favourite theme of both historians and German generals. This powerful combination has long dominated the assessment of the campaign. It is not the purpose of this essay to minimize the importance of Allied air operations, in particular the attacks on the German communication system. Rather, it is an attempt to examine in some detail the actual results of that operation in order to obtain a clearer understanding of its place among the many other ingredients which combined to defeat the German Army in Normandy.