The Sopwith Triplane appearing in early 1917, became the new opponent to their Albatross D.III. The Fokker company, who was developing (at the same time) a new project; the D.VI biplane, received an order from the Idflieg for a new triplane aircraft. First, German air command proposed to copy the Sopwith Triplane (like Pfalz Flugzeugwerke previously had copied the Morane designs). But Anthony Fokker in the short term adopted the D.VI to triplane standards. In August of 1917, two pre-production aircraft reached the front for combat trials.
The new plane very quickly received the best performance reports from it pilots, especially for its incredible maneuverability. Fokker's new plane was soon received by Jagdgeschwader 1 - a superb and elite German fighter unit named "The Von Richthofen Flying Circus". This plane was ideal for fighting at low-altitudes.
During September of 1917, JG1 had incurred a few flying accidents (wing failures were found); two pilots were killed and all the Dr.I's were grounded for investigation. In fact, the Dr.I was a very sensitive plane; it was not forgiving of even the smallest of mistakes by its pilots. The plane was returned to service the next month, by this time it became evident that the Dr.I couldn't oppose the new and more powerful allied fighters.
About 300 planes of this type were built in total by the Fokker Company, many of them serving until the end of the war.
After the death of Von Richthoffen in aerial combat on April 21st 1918, the Flying Circus was headed by another famous ace, Wilhelm Reinhardt (20 victories, Pour Le Merite), but two months later he was killed in a flying accident while flying the new Dornier D.I. The Last commander of JG1 was Hermann Goring (22 victories, PLM), his command lasted until the Armistice.
Many famous aces also flew the Dr.I, such as, Ernst Udet (62 victories, PLM), Ulrich Neckel (30 victories, PLM), Erich Loewenhardt (53 victories, PLM), Josef Carl Jacobs (41 victories, PLM).