When World War I began in August 1914, the airplane had already proven its worth as an intelligence gathering 'eye-in-the-sky.' Aircraft soon became indispensable to armies on both sides, and the attempt to drive enemy planes away began in earnest. Local air superiority was incorporated into battlefield strategy, and the use of aircraft to conduct offensive operations would change warfare as dramatically as the first firearms 300 years before. In The Origin of the Fighter Aircraft, historian Jon Guttman tells the engrossing story of how one of the most amazing inventions became an integral component of warfare. The first true fighter plane whose primary function was to destroy enemy aircraft--whether scouts, balloons, bombers, or other fighters--emerged at the end of 1915, and with it a new glamorized 'knight of the air' was born: the ace, a pilot who brought down five or more opponents.