 The unsteadiness of the empire was ever increasing under Yazdegerd II, who had an uneasy relationship with the aristocracy and was facing a great challenge by the Hephthalites in the east.At the beginning of Yazdegerd II's reign, he suffered several defeats at the hands of the Hephthalites, for which he put the blame on the Christians, due to much of his cavalry consisting of Iberians and Armenians.Persecutions of Christians first started in 446 with the Christian nobles of Karkh in Mesopotamia.