King George VI prepares to leave RAF Northolt in 1938. He later visited the station during the Battle of Britain, watching from the Operations Room as fighters engaged the Luftwaffe over southern England. The King later wrote to the Secretary of State for Air: "Please convey my warmest congratulations to the Fighter Squadrons who in recent days have been so heavily engaged in the defence of our country. I, like their compatriots, have read with ever-increasing admiration the story of their daily victories."

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