Junkers was unable to fulfil first major production contract for J4 (Idflieg designation J.I). Junkers-Fokker-Werke formed at Dessau 20 October 1917, equal shares held by 2 principals. Built 227 J.I, 41 J9 (D.I) and 43 J10 (CL.I); impossible clash of personalities and Fokker walked out mid-1918.