The Battle of Britain was the first major military campaign fought entirely by air forces. After the fall of France, Hitler planned an invasion of Britain (Operation Sea Lion), but first needed to destroy the Royal Air Force (RAF) to gain air superiority. Throughout the summer of 1940, the German Luftwaffe launched massive raids on British airfields, factories, and eventually cities in 'The Blitz.' Despite being outnumbered, the RAF had the advantage of the newly developed Dowding System, which integrated RADAR technology to track incoming flights. The courage of the pilots, flying iconic Spitfires and Hurricanes, eventually forced Hitler to postpone the invasion indefinitely. In a famous tribute, Churchill stated, 'Never in the field of human conflict was so much owed by so many to so few.'