The original Flying Circus
In World War I, the Imperial German Air Service (after 1916, "Deutsche Luftstreitkräfte" or simply the German Air Force) became the first military aviation arm to begin organizing combat aircraft in large formations. On June 24, 1917, four squadrons (Jasta) of fighters - Jastas 4, 6, 10 and 11 - were combined into a single unit which was named Jagdgeschwader I (JG 1), which Google and others translate into English as "Fighter Wing."
This particular unit had two notable characteristics, at least as far as its Allied opponents were concerned. For one thing, it was commanded by a young fighter pilot named Baron Manfred von Richthofen - also known as the Red Baron. For the second, its units adopted a scheme of painting their aircraft in bright colors according to which Jasta they belonged to, in order to make coordination during dogfights easier (resuming formation, coordinating targets or areas, etc.)
JG 1 began to go into combat with two or more Jastas simultaneously, often with all 40 aircraft in the air at once. They were led by their commander in his distinctive bright red Fokker Triplane, and the whole coordinated colorful phenomenon came to be known, to the Allies, as "Manfred von Richthofen's Flying Circus."
Over the course of the war, JG 1 destroyed 644 aircraft for a loss of 52-54 pilots (sources disagree) including, of course, their famous commander who was shot down in 1918.
Iron Noder 2010