The Defence of the Reich (German: Reichsverteidigung) is the name given to the strategic defensive aerial campaign fought by the Luftwaffe air arm of the combined Wehrmacht armed forces of Nazi Germany over German-occupied Europe and Nazi Germany during World War II. Its aim was to prevent the destruction of German civilians, military and civil industries by the Western Allies. The day and night air battles over Germany during the war involved thousands of aircraft, units and aerial engagements to counter the Allied strategic bombing campaign. The campaign was one of the longest in the history of aerial warfare and with the Battle of the Atlantic and the Allied Blockade of Germany was the longest of the war. The Luftwaffe fighter force defended the airspace of German-occupied territory aga