The Battle of Britain during World War II began in July 1940, when Germany turned its attention to Great Britain after defeating France, and did not fully end until May 1941, by which time both Berlin and London had been heavily bombed and tens of thousands of civilians had been killed or wounded.
In June 1940, German chancellor Adolf Hitler, after having easily defeated France, turned his sights on Great Britain. The strategy for the Battle of Britain, known as Operation Sea Lion, was for the Luftwaffe (the German air force) to defeat the British Royal Air Force (RAF) and then the British Royal Navy. Airfields in the occupied countries of France, Belgium, the Netherlands, and Norway were to be used as launching points for the attack.
Throughout July and August, the Luftwaffe subjected the British coast to incessant bombardment, both night and day. The British, however, put new radar technology to good use and managed to concentrate their forces in key defensive areas. During August 24-29, the British retaliated by staging a bomb attack against Berlin. Though the initial bombing incurred little damage, it was psychologically damaging to the Germans. A second night of bombardment produced greater casualties.
By September, the Germans changed their strategy, concentrating their attacks on London. Waves of German bombers flew over the city, incurring high civilian casualty rates; as many as 3,000 people were injured every day, and between 300 and 600 people killed. Despite the heavy losses, the British kept fighting, and the RAF was able to concentrate its waning forces in defense of London, inflicting such heavy damage on the German fighter planes and bombers that the continual bombings had to be called off.
By October 12, Hitler called off Operation Sea Lion altogether. The battle, however, was not entirely over. In November, the German air force renewed its attacks in the form of a blitzkrieg (lightning attack). This time, the purpose was not to gain permanent air control but to inflict damage. The town of Coventry was nearly demolished by 500 German bombers. London, as well, was devastated. The Germans kept up the "blitz" until May 1941, killing 43,000 British civilians and seriously wounding 51,000 others.