Around 350, the Sasanian Emperor Shapur II (ruled 309 to 379) had to interrupt his conflict with the Romans, and abandon the siege of Nisibis, in order to face nomadic threats in the east: he was attacked in the east by Scythian Massagetae and other Central Asian tribes. Around this time, Xionite/Huna tribes, most likely the Kidarites, whose king was Grumbates, make an appearance as an encroaching threat upon Sasanian territory as well as a menace to the Gupta Empire (320–500).