On what became commemorated as Battle of Britain Day, the Royal Air Force flew roughly 630 sorties against waves of German bombers and fighters attacking London. British pilots shot down around 60 German aircraft against the loss of about 26 of their own, a lopsided result that convinced Hitler's high command the Luftwaffe could not achieve the air superiority needed for Operation Sea Lion, the planned invasion of Britain.
By mid-September 1940, the Luftwaffe had spent weeks pounding RAF airfields and radar stations before shifting to bombing London itself, hoping to break British morale and draw Fighter Command into a final annihilating battle. Hermann Göring believed the RAF was nearly finished, down to its last squadrons of Spitfires and Hurricanes.
He was wrong. On this Sunday morning, radar stations along the Chain Home network detected two massive waves of German aircraft crossing the Channel, and Air Vice-Marshal Keith Park scrambled every available squadron from 11 Group. Winston Churchill happened to be visiting Park's underground operations bunker at Uxbridge that day and watched the battle unfold on the plotting tables in real time, later asking Park what reserves remained. Park's grim answer, that none were left, stuck with Churchill for the rest of his life.
The British public, watching vapor trails and parachutes fill the sky over London, sensed something decisive was happening. German bomber crews, expecting a beaten enemy, instead met ferocious resistance that scattered their formations before they reached their targets. Two days later, Hitler indefinitely postponed the invasion. The date is still marked in Britain every year as Battle of Britain Day.
Key people: Winston Churchill, Keith Park, Hermann Göring