1915: The Royal Flying Corps' first dedicated air combat formation, 11 Squadron, was equipped with the two-seat Vickers Gunbus. Meanwhile, Captain L G Hawker, 6 Squadron, flying a Bristol Scout with an improvised machine-gun mounting, damaged one German reconnaissance aircraft, forced another down, and destroyed in flames a third, during a single sortie over the Ypres salient. Hawker was awarded the Victoria Cross and went on to become the RFC's leading fighter pilot. He was killed in action on 23 November 1916, during a dogfight with Leutnant Manfred Freiherr von Richthofen: he was the Red Baron's eleventh and most distinguished victim.

1940: The Luftwaffe launched significant attacks on Dover harbour and a Channel convoy; each was intercepted by Fighter Command.

1943: Bomber Command returned from an overnight raid on Hamburg, Germany's most important port, having lost only twelve aircraft from a force of 791 bombers; the raid, the start of the Battle of Hamburg, had marked the first use by the RAF of Window : vast quantities of aluminium foil strips, backed with paper and blackened so as not to shine in searchlight beams, had been dropped by the bombers. The foil strips had been cut to the correct length to act as dipole reflectors for the German radar wavelengths as they slowly fluttered to earth. The result was unprecedented confusion in the Luftwaffe's air defence system, as radar screens were swamped by a mass of returns. The raid inflicted heavy damage on the city.

Target-markers dropped by the Pathfinders were sufficiently accurate to allow 2,284 tons of bombs to fall on the centre and north-west suburbs of the city in 50 minutes. However, a far more devastating raid was to follow a couple of days later.

Keen to exploit the advantages of Window before the Luftwaffe learnt to cope with it, the evening of 25 July saw Bomber Command set out for another high priority target, Essen, home to the vast Krupps armament complex. The Krupps works received its most damaging attack of the war; indeed, Dr Gustav Krupp was so horrified by the state of the factory the next morning that he suffered a stroke.