The Messerschmitt Bf110 was originally designed as a long-range escort fighter and Zersto"rer (destroyer) aircraft. This twin-engine, three-seat heavy fighter was built in response to a Luftwaffe requirement announced in 1934, with the first prototype flying in 1936. Late in 1938 when DB 601 B-1 engines finally became available, production of the Bf110C could proceed apace. There were seven major variants of the Bf110C, and these were the first to see widespread operational use. While they enjoyed some success in the Polish and French campaigns, they were hopelessly outclassed during the Battle of Britain where they proved unable to protect Luftwaffe bombers from more nimble Spitfires and Hurricanes.