The Messerschmitt Bf 110, often called Me 110, was a twin-engine heavy fighter (Zerstörer - German for "Destroyer") in the service of the Luftwaffe during World War II. Hermann Göring was a proponent of the Bf 110, and nicknamed it his Eisenseiten ("Ironsides"). The Bf 110's lack of agility in the air was its primary weakness. This flaw was exposed during the Battle of Britain, when some Bf 110-equipped units were withdrawn from the battle after very heavy losses and redeployed as night fighters, a role to which the aircraft was well suited.