The film endeavoured to be an accurate account of the Battle of Britain, when in the summer and autumn of 1940 the British RAF inflicted a strategic defeat on the "Luftwaffe" and so ensured the cancellation of Operation Sea Lion – Adolf Hitler's plan to invade Britain. The film is notable for its spectacular flying sequences, in contrast with the unsatisfactory model work seen in "Angels One Five" (1952). It was on a far larger scale than had been seen on film before and this made the film's production very expensive.