"As I can remember, as a schoolboy in south London, there was no dismay among my family and their friends at the sight of contorted vapour trails high over us as Fighter Command and the Luftwaffe fought it out in the blue summer sky – only a sense of excitement. Looking back now as a historian, it is clear to me that in 1940 the British nation was blessed by an inner certainty that, just as the Navy had seen off Philip II of Spain in 1588 and Napoleon in 1805, so now the Royal Air Force and the Navy together would see off that funny little man with the toothbrush moustache and his fat chum in the gawdy uniform covered in medals. In that certainty, there was truly an element of the heroic."