The division between the Church of the Persian Empire and the Churches of Rome and Constantinople goes back to the disputes over the legitimacy of the terms "mother of God" and "mother of Christ" for the Virgin Mary, that came to a head at the Council of Ephesus in 431. The Assyrian Church had adopted radical Antiochene Christology, as articulated by Nestorius and Theodore of Mopsuestia. They have been sometimes, erroneously, called Nestorian. This appellation is rejected by the Catholic Church.