The Messerschmitt Bf 110, often (erroneously) called Me 110, was a twin-engine heavy fighter (Zerstörer – German for "Destroyer" – a concept that in German service involved a long-ranged, powerful fighter able to range about friendly or even enemy territory destroying enemy bombers and even fighters when located) 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"). Development work on an improved type to replace the Bf 110, the Messerschmitt Me 210 began before the war started, but its teething troubles resulted in the Bf 110 soldiering on until the end of the war in various roles, alongside its replacements, the Me 210 and the Me 410.