The most successful fighter pilots who took part in aerial battles during the First World War were called Flying Aces. The term first appeared in 1915 when French newspapers described Adolphe Pègoud as un As after he became the first pilot to shoot down five German aircraft. Ace, the highest in a deck of cards, was current sports slang in France, meaning 'Champion'. In 1916 during the Battle of Verdun the French fighter units began publishing the scores of individual pilots. The German Air Service followed the example of France but their pilots were only listed when they had achieved eight confirmed victories.
	At the beginning of the war, Anthony Fokker, a Dutch designer who had set up an aircraft factory in Schwerin, Germany, developed a machine-gun that could fire through revolving propeller blades. By the autumn of 1915 Fokker was fitting his Eindecker monoplanes with interrupter gear, therefore producing the first true fighter aircraft. Also called a synchronising gear, the propeller was linked by a shaft to the trigger to block fire whenever they were in line. German pilots such as Max Immelmann and Oswald Boelcke began destroying large numbers of British aircraft using their synchronised machine-guns. Immelmann destroyed 17 Allied aircraft in his Eindecker before being shot down and killed on 15 June 1916. Boelcke went on to claim 40 victims before he was also killed in October 1916. Pilots such as Immelmann and Boelcke, who had more than eight victories, became known as Kannonen and were awarded Germany's highest award for bravery; the Orden Pour le Mérite. It was not long before Britain and France began fitting synchronised machine-guns to their aircraft and pilots such as René Fonck and William Bishop developed reputations as les As Volants or Flying Aces.
	The Royal Flying Corps also began publishing figures in 1916. It was also decided that British Empire Flying Aces who achieved eight victories would be awarded the Distinguished Flying Cross. Pilots who won this award included Mick Mannock (73 victories), William "Billy" Bishop (72), Raymond Collishaw (68), James McCudden (58), William Barker (50), Robert Little (47), Albert Ball (44), and Alfred Atkey (38). France's most successful les As Volants included René Fonck (75), Georges Guynemer (53), Charles Nungesser (43) and Georges Madon (41). Highest scoring German Kannonen were idolized by their nation and included Ernst Udet (62), Erich Löwenhardt (54), Werner Voss (48), and Bruno Loerzer (44). But it was Manfred von Richthofen, the 'Red Baron', with 80 victories, who achieved the highest figure during the First World War.

The figures published in the newspapers were not always accurate. Dogfights often involved large numbers of aircraft and it was not always clear who was really responsible for the actual 'kill'. Obtaining a confirmed victory involved the inspection of the wreckage, and this was of course impossible when the aircraft had come down behind enemy lines. The publication of these figures helped to build up morale during the war. They were also used to persuade young men to join the armed forces and to encourage experienced pilots to compete with their comrades.