<P> Hitler postponed the Sealion invasion on 13 October "until the spring of 1941". It was not until Hitler's Directive 21 was issued, on 18 December 1940, that the threat to Britain of invasion finally ended . </P> <P> During the battle, and for the rest of the war, an important factor in keeping public morale high was the continued presence in London of King George VI and his wife Queen Elizabeth . When war broke out in 1939, the King and Queen decided to stay in London and not flee to Canada, as had been suggested . George VI and Elizabeth officially stayed in Buckingham Palace throughout the war, although they often spent weekends at Windsor Castle to visit their daughters, Elizabeth (the future queen) and Margaret . Buckingham Palace was damaged by bombs which landed in the grounds on 10 September and, on 13 September, more serious damage was caused by two bombs which destroyed the Royal Chapel . The royal couple were in a small sitting room about 80 yards from where the bombs exploded . On 24 September, in recognition of the bravery of civilians, King George VI inaugurated the award of the George Cross . </P> <P> Overall, by 2 November, the RAF fielded 1,796 pilots, an increase of over 40% from July 1940's count of 1,259 pilots . Based on German sources (from a Luftwaffe intelligence officer Otto Bechtle attached to KG 2 in February 1944) translated by the Air Historical Branch, Stephen Bungay asserts German fighter and bomber "strength" declined without recovery, and that from August--December 1940, the German fighter and bomber strength declined by 30 and 25 percent . In contrast, Williamson Murray, argues (using translations by the Air Historical Branch) that 1,380 German bombers were on strength on 29 June 1940, 1,420 bombers on 28 September, 1,423 level bombers on 2 November and 1,393 bombers on 30 November 1940 . In July--September the number of Luftwaffe pilots available fell by 136, but the number of operational pilots had shrunk by 171 by September . The training organisation of the Luftwaffe was failing to replace losses . German fighter pilots, in contrast to popular perception, were not afforded training or rest rotations unlike their British counterparts . The first week of September accounted for 25% of the Fighter Command, and 24% of the Luftwaffe's overall losses . Between the dates 26 August--6 September, on only one day (1 September) did the Germans destroy more aircraft than they lost . Losses were 325 German and 248 British . </P> <P> Luftwaffe losses for August numbered 774 aircraft to all causes, representing 18.5% of all combat aircraft at the beginning of the month . Fighter Command's losses in August were 426 fighters destroyed, amounting to 40 per cent of 1,061 fighters available on 3 August . In addition, 99 German bombers and 27 other types were destroyed between 1 and 29 August . </P>

How many german pilots died in the battle of britain