persecuted Christians; Battle of Avavir 451
In the beginning of his reign, Yazdegerd II quickly attacked the Eastern Roman Empire with a mixed army of various nations, including his Indian allies, to eliminate the threat of a Roman buildup. (The Romans had been constructing fortifications in the nearby Persian territory of Carrhae, in anticipation of subsequent expeditions.) The Romans were caught by surprise, and only a heavy flood prevented a Persian advance deep into in Roman territory. The Byzantine Emperor, Theodosius II (408450), asked for peace and sent his commander personally to Yazdegerd II's camp. In the ensuing negotiations in 441, both empires promised not to build any new fortifications in their border territories. Yazdegerd II, in spite of having the upper hand, did not make further demands on the Romans due to incursions by Kidarites in Parthia and Khwarezmia. He gathered his forces in Neishabur in 443 and launched a prolonged campaign against Kidarites. After numerous battles, he crushed them and drove them out beyond Oxus river in 450.
During his eastern campaign, Yazdegerd II grew suspicious of Christians in the army and the nobility and expelled many of them. He then persecuted the Christians and, to a much lesser extent, Jews. Advancing his pro-Zoroastrian policy, he crushed an uprising of Armenian Christians in the Battle of Vartanantz in 451.
In his later years, Yazdegerd II became engaged again with Kidarites until his death in 457. Other than his strict religious policies and minorities persecution, commoners saw him as a just, moderate ruler.
