Both sides in the crisis over the title Theotokos (“God-Bearer”) as applied to Mary, have appealed to Pope Celestine, who has already been offended by Nestorius' tactlessness.

Celestine holds a church council in Rome in August 430 that decides correct Christology requires the use of the term Theotokos and requests Nestorius to disown his errors.

When Bishop Cyril of Alexandria, who has been authorized to execute the sentence upon Nestorius, produces a string of provocative anathemas for him to subscribe to or face excommunication, Nestorius and his allies take alarm, and he persuades Eastern emperor Theodosius to convene a general church council.

It is Nestorius's hope that the council will result in the condemnation of Cyril.