Shapur II
After a prolonged struggle (353–358) they were forced to conclude an alliance, and their king Grumbates accompanied Shapur II in the war against the Romans, agreeing to enlist his light cavalrymen into the Persian army and accompanying Shapur II. The presence of "Grumbates, king of the Chionitae" and his Xionites with Shapur II during campaigns in the Western Caspian lands, in the area of Corduene, is described by the contemporary eyewitness Ammianus Marcellinus: