 After he managed to secure the eastern portion of his empire against the Hephthalite incursions, Yazdegerd II shifted his focus on Armenia and Caucasian Albania to defend the Caucasus with the Romans against the increasing Hun threat.The policies of Yazdegerd II have been the matter of discussion; Arabic and Persian sources emphasize his personal piety and hostility towards the aristocracy, whilst Armenian and Syriac sources describe him as a religious fanatic.The latter aspect is often stressed in modern historiography.