Battle of Britain Day, 15 September 1940, is the day on which a large-scale aerial battle in the Battle of Britain took place. In June 1940, the Wehrmacht had conquered most of Western Europe and Scandinavia. At that time, the only major power standing in the way of a German-dominated Europe was the British Empire and the Commonwealth. After having several peace offers rejected by the British, Adolf Hitler ordered the Luftwaffe to destroy the RAF in order to gain air superiority or air supremacy as a prelude to launching Operation Sea Lion, an amphibious assault by the Wehrmacht (German armed forces) onto the British mainland.In July 1940, the Luftwaffe started by closing the English Channel to merchant shipping. In August, Operation Adlerangriff (Eagle Attack) was launched against RAF air