High Command (, OHL) reorganised by creating specialist fighter, bomber and reconnaissance units such as single-seat fighter squadrons (, , hunting squadrons) to counter the Royal Flying Corps and the French . Commanders Fighter unit organization The initial deployment of fighter aircraft in the summer of 1915 occurred within the , which were being equipped with one or two of the new Fokker Eindecker fighter aircraft for each unit, starting with the five Fokker M.5K/MG production prototypes of the Eindecker, bearing serial numbers E.1/15 through E.5/15. The buildup of the fighter force rapidly progressed with regular lMG 08 "Spandau"-armed production examples of the Fokker E.I following the deliveries of the M.5K/MG airframes late in the summer of 1915, with early E.Is going to aces like Max Immelmann, who received IdFlieg serial number E.13/15 in August 1915. The first step towards specialist fighter-only aviation units within the German military was the establishment of (single-seat battle unit, abbreviated as KEK) formations by Inspektor-Major Friedrich Stempel in February 1916. These were based around Eindeckers and other new fighter designs emerging, like the Pfalz E-series monoplanes, that were being detached from their former FFA units during the winter of 1915–1916 and brought together in pairs and quartets at particularly strategic locations, as KEK units were formed at Vaux, Avillers, Jametz, Cunel and other strategic locations along the Western Front, to act as (aerial guard force) units, consisting only of fighters. Following the era of the KEK units through the summer of 1916, (hunting squadrons), established by the reorganization that started in the late summer of 1916 were fielded by four kingdoms of the German Empire. Individually - each of these units was often known by the abbreviation . The Kingdom of Prussia was predominant, with a fighter force eventually comprising 67 squadrons. The Kingdom of Bavaria formed ten of these units, the Kingdom of Saxony formed seven and the Kingdom of Württemberg four. On 24 June 1917, the brought a quartet of squadrons together to form its first fighter wing, Royal Prussian , incorporating Jastas 4, 6, 10 and 11, and set the pattern for using Roman numerals in the in the titles of such larger units. Manfred von Richthofen was moved up from command of Jasta 11 to command JG I. Much as Jasta 2 had been renamed as in December 1916 after Oswald Boelcke, Germany's top fighter tactician had been lost in