During the latter half of the 1930s, the fear of a possible aerial knock-out on Great Britain became a dominating factor in the formulation of national policy. This text examines how justified these pre-war fears were in light of the Luftwaffe's capabilities in 1939 and describes the bombing attacks on Britain during the years that followed, together with the operations of the defences to parry them. From the start, the air defences proved able to take a heavy toll on the bombers attacking Britain by day. By night it was a different matter. Initially, the fighter and gun defences were lucky if between them they were able to knock out one or two bombers out of three or four hundred involved in a night attack. From this poor beginning the defences improved out of all recognition and when the Germans launched a series of attacks on London early in 1944, it cost them one bomber and four trained crewmen for every five British civilians killed. Blitz on Britain makes compelling reading for anyone interested in the Luftwaffe's wartime raids on Britain, and how the air defences ultimately succeeded in defeating this long running aerial onslaught.