The Messerschmitt Bf 109, sometimes incorrectly called the Me 109 (most often by Allied pilots and aircrew), is a German World War II fighter aircraft designed by Willy Messerschmitt and Robert Lusser during the early to mid-1930s. The "Bf 109" designation was issued by the German ministry of aviation and represents the developing company Bayerische Flugzeugwerke (at which the engineer Messerschmitt led the development of the plane) and a rather arbitrary figure. It was one of the first truly modern fighters of the era, including such features as all-metal monocoque construction, a closed canopy, and retractable landing gear. It was powered by a liquid-cooled, inverted-V12 aero engine.
The Bf 109 first saw operational service during the Spanish Civil War and was still in service at the dawn of the jet age at the end of World War II, during which time it was the backbone of the Luftwaffe's fighter force. From the end of 1941, the Bf 109 was steadily being supplemented by the superior Focke-Wulf Fw 190.
Originally conceived as an interceptor, later models were developed to fulfill multiple tasks, serving as bomber escort, fighter-bomber, day-, night-, all-weather fighter, ground-attack aircraft, and as reconnaissance aircraft. It was supplied to and operated by several states during World War II, and served with several countries for many years after the war. The Bf 109 was the most produced fighter aircraft in history, with a total of 33,984 airframes produced from 1936 up to April 1945.
The Bf 109 was flown by the three top-scoring German fighter aces of World War II, who claimed 928 victories among them while flying with Jagdgeschwader 52, mainly on the Eastern Front, as well as by Hans-Joachim Marseille, the highest scoring German ace in the North African Campaign, scoring 158 victories. It was also flown by several other aces from Germany's allies, notably Finn Ilmari Juutilainen, the highest scoring non-German ace on the type with 58 victories flying the Bf 109G, and pilots from Italy, Romania, Croatia, Bulgaria and Hungary. Through constant development, the Bf 109 remained competitive with the latest Allied fighter aircraft until the end of the war.