Important Days in the Battle: 15 September

A week after their change of tactics and the great raid of 7 September on London, the Germans planned another massive assault which, they considered, would finally shatter Fighter Command's resistance and open the path for a successful invasion of Britain. However, during the intervening seven days, the defences had recovered from the strain they had been under when the Luftwaffe had targetted 11 Group's airfields. Fighter production was continuing at a highly satisfactory level and, on 14 September, operational pilot strength was the highest it had been since the start of the Battle.

By 11.00am it was obvious that the massing of German aircraft above the French coast signalled an imminent large-scale attack. The plan was weakened by two factors. Firstly, the offensive came in two distinct waves, giving defending aircraft time to re-fuel and re-arm in between. Secondly, in full view of British radar as always, the usual feints and clever diversionary manoeuvres were not employed. Therefore, Fighter Command was able to deploy as many as seventeen squadrons in good positions ready to meet threats from the east and south.

The first attack coming in over east Kent at 11.30am was engaged all along its route to London and on its return flight. Bomber formations were smashed, making accurate bombing impossible and, although bombs were scattered over a wide area of London and its suburbs, consequently little damage was caused.

The second and heavier attack came in at 2.00pm in three waves on a ten mile front over north Kent. Once again Fighter Command was able to oppose in great strength. Most of the fighting took place over London and its outskirts east to Dartford. A very large bombload was dropped but, just as in the morning, it was very widely spread. Some damage occurred to public utilities, railways and riverside targets in West Ham and Erith but it was nowhere near as severe as that sustained on 7 September. Fortunately, when the action over London was at its height, a raid on Portland naval base caused little damage and another failed to land any bombs on the vitally-important Spitfire factory in Southampton.

15 September was a day of heavy and sustained fighting. The Luftwaffe had flown over 1,000 sorties. Euphoric British pilots and anti-aircraft gunners claimed a magnificent total of 185 victims. Although the real count was 60, the highest German losses since 18 August, for once figures did not matter. It was obvious to both sides that German tactics had failed. The German Air Force had not swept Fighter Command from the skies. It had not gained air supremacy. Although fighting continued, sometimes heavily, for another few weeks into October, the action on 15 September had seen an overwhelming and decisive defeat for the Luftwaffe. For this reason, this date is celebrated in the United Kingdom as Battle of Britain Day.