Ephesus (431): Unity Under Pressure
Historical Backdrop
The Council of Ephesus was convened in 431 AD to address the teachings of Nestorius, Patriarch of Constantinople, who had challenged the use of the title Theotokos ("God-bearer") for the Virgin Mary. His position threatened to divide Christ’s human and divine natures too sharply. Emperor Theodosius II called the council, which was presided over by Cyril of Alexandria and took place under highly tense and politically charged circumstances.
Did Cyril act on behalf of Pope Celestine I?
Yes. Before the council convened, Pope Celestine I held a Roman synod in 430 that condemned Nestorius. He then authorized Cyril of Alexandria to act on Rome’s behalf, effectively delegating papal authority to enforce the decision if Nestorius did not recant.
Cyril’s famous twelve anathemas against Nestorius were drafted and sent to him prior to the council. These anathemas, with Roman support, became central to the Council of Ephesus’s condemnation of Nestorius.
How did the papacy view its role at Ephesus?
Pope Celestine saw the Roman See as having **final judgment** in doctrinal matters, and his delegation of authority to Cyril suggests that Rome considered itself **doctrinally decisive**, even if physically absent. Papal legates arrived late, but when they did, they praised the council for having already judged rightly—indicating their approval functioned more as **ratification** than deliberation.
“It is a matter of necessity that every Church should agree with the Roman Church.” — Pope Celestine I, quoting Pope Damasus I
Was papal authority seen as essential or supplementary?
This is where Catholic and Orthodox interpretations diverge.
Catholic view:
Rome’s role was essential. Cyril acted under papal authority, and the council’s decisions were legitimate precisely because they aligned with and were authorized by the Roman See. This is seen as an example of
Orthodox view:
While acknowledging Rome’s support and importance, the Orthodox emphasize that **Cyril acted as patriarch of Alexandria**, presiding over the council by imperial appointment and local ecclesial stature. Papal involvement strengthened the verdict, but it was not **essential** to its validity.
So who led the council—Cyril or the pope?
Cyril presided, made key doctrinal arguments, and managed the proceedings. Rome’s legates arrived late but affirmed the decisions already made. This points to a **shared authority**, with Cyril leading the council and Rome providing theological weight and post hoc ratification.
**Side Note**
St. Cyril clearly saw himself as both the activing patriarch of Alexandria and as a delegate with delegated authority from the bishop of Rome. In 430, Pope Celestine I held a synod in Rome that condemned Nestorius and instructed Cyril to execute the sentence if Nestorius did not recant. Cyril wrote to Nestorius saying, "...with the authority of our most holy and pious brother Celestine, bishop of the Roman Church..." showing that he explicitly linked his action to papal backing, even though he himself was Patriarch of Alexandria. The question then becomes, why would Cyril invoke papal authority rather than act solely in his own name if the patriarchs were truly "equal"? The Orthodox would say that they were dealing with a deeply divided episcopate and that by invoking both Alexandria and Roman authority, Cyril was creating a united front, bolstering the legitimacy of his theological stance, and signaling to the emperor and Eastern sees taht Rome and Alexandria were in agreement. This would have been very difficult to ignore politically and theologically.
Conclusion
The Council of Ephesus demonstrates a moment of powerful cooperation between East and West. From a Catholic lens, it showcases papal primacy at work through delegated authority. From an Orthodox view, it highlights the conciliar model, with Rome as an honored supporter but not the source of legitimacy.
What remains clear is that both traditions revere Ephesus as an ecumenical council, united in condemning Nestorianism and affirming the full divinity and humanity of Christ in the womb of the Virgin Mary, the Theotokos. This moment is also one of the clearest examples of how conciliar Orthodoxy and early papal primacy coexisted in the first millennium.