The battle lasted many months, but the German air force (the Luftwaffe) could not beat the RAF.
Actually, the RAF were nearly beaten, but Hitler did not know this. Then one day, one of his planes accidentally bombed London instead of an airfield. The British then bombed Berlin, the capital of Germany. Hitler was in a rage and he turned his bombers on British cities instead of airfields. This gave the RAF time to recover and eventually beat the Luftwaffe.