By June 1940, northern France had fallen to German forces and Great Britain stood alone in Europe against the Nazi onslaught. Hitler's plan was to cripple the British Royal Air Force (RAF) then invade Britain by sea. With the Luftwaffe's greater number of aircraft and more experienced pilots, victory over the RAF seemed certain. But Hitler and his generals misjudged the strength of Britain's defenses, the skill of its military leaders, and the determination of its people. What was intended to be a short, sharp attack became a long-running and costly battle played out in the skies over England. This book explores the strategies, technology, and long-term consequences of a fierce battle that changed the course of World War II.