The first division between Syriac Christians occurred in the 5th century, when Upper Mesopotamian based Assyrian Christians of the Sassanid Persian Empire were separated from those in The Levant over the Nestorian Schism. This split owed just as much to the politics of the day as it did to theological orthodoxy. Ctesiphon, which was at the time the Sassanid capital, eventually became the capital of the Church of the East. During the Christian era Nuhadra became an eparchy within the Assyrian Church of the East metropolitanate of Ḥadyab (Erbil).