The Battle of Berlin was the British bombing campaign on Berlin from November 1943 to March 1944. Not limited solely to Berlin, the campaign targeted other German cities as well, to prevent the concentration of defences in Berlin. The campaign was launched by Arthur "Bomber" Harris, AOC of RAF Bomber Command in November 1943. Harris believed this could be the blow that broke German resistance: "It will cost us between 400 and 500 aircraft. It will cost Germany the war". By this time he could deploy over 800 long-range bombers on any given night, equipped with new and more sophisticated navigational devices such as H2S radar.