Gundam AN-01 Tristan was operated in secret by private army Birnam. It was based on Gundam NT-1 Alex. The Earth Federation Force's dedicated machine for Newtypes that was completed and delivered to Side 6 in U.C.0079. and was made using machines that were half-damaged in battle or machines that could no longer be sent to battle. The head, in particular, and the backpack, chest, and waist were newly created.