First Hunnic-Sasanian War

The first Hunnic invasion of the Sasanian Empire was from 399-400. This invasion was initially successful, coming close to the capital of the empire at Ctesiphon; however, they were defeated badly during the Persian counterattack which also resulted in the death of Kursich and Basich.

Source
https://en.wikipedia.org/wiki/Huns#Before_Attila