The Fourth Ecumenical Synod of 451 took place in the Church of Saint Euphemia in Chalcedon, where her sacred relics were kept. The Patriarch of Constantinople at this Synod was Anatolios, while the Pope of Rome was Leo the Great. Information about the miracle of Saint Euphemia comes from two letters: one from the the Synod to Pope Leo and the other from Patriarch Anatolios to Pope Leo. Though the passages are a bit obscure about the miracle, it says that the definition of faith was delivered by Saint Euphemia as her own confession of faith and confirmed by the holy Fathers present. It seems clear that Pope Leo already knew of the miracle, or it was common knowledge by the time these two letters were issued.
The two letters are as follows, with the relevant information about the miracle highlighted:
LETTER 98: FROM THE SYNOD OF CHALCEDON TO LEO OF ROME
The great and holy and universal Synod, which by the grace of God and the sanction of our most pious and Christ-loving Emperors has been gathered together in the metropolis of Chalcedon in the province of Bithynia, to the most holy and blessed archbishop of Rome, Leo.
“Our mouth was filled with joy and our tongue with exultation.” This prophecy grace has fitly appropriated to us for whom the security of religion is ensured. For what is a greater incentive to cheerfulness than the Faith? what better inducement to exultation than the Divine knowledge which the Saviour Himself gave us from above for salvation, saying, “go ye and make disciples of all the nations, baptizing them into the name of the Father, and of the Son, and of the Holy Ghost, teaching them to observe all things that I have enjoined you.” And this golden chain leading down from the Author of the command to us, you yourself have steadfastly preserved, being set as the mouthpiece unto all of the blessed Peter, and imparting the blessedness of his Faith unto all. Whence we too, wisely taking you as our guide in all that is good, have shown to the sons of the Church their inheritance of Truth, not giving our instruction each singly and in secret, but making known our confession of the Faith in conceit, with one consent and agreement And we were all delighted, reveling, as at an imperial banquet, in the spiritual food, which Christ supplied to us through your letter: and we seemed to see the Heavenly Bridegroom actually present with us.
For if “where two or three are gathered together in His name,” He has said that “there He is in the midst of them,” must He not have been much more particularly present with 520 priests, who preferred the spread of knowledge concerning Him to their country and their ease? Of whom you were, chief, as the head to the members, showing your goodwill in the person of those who represented you; whilst our religious Emperors presided to the furtherance of due order, inviting us to restore the doctrinal fabric of the Church, even as Zerubbabel invited Joshua to rebuild Jerusalem.
And the adversary would have been like a wild beast outside the fold, roaring to himself and unable to seize any one, had not the late bishop of Alexandria thrown himself for a prey to him, who, though he had done many terrible things before, eclipsed the former by the latter deeds; for contrary to all the injunctions of the canons, he deposed that blessed shepherd of the saints at Constantinople, Flavian, who displayed such Apostolic faith, and the most pious bishop Eusebius, and acquitted by his terror-won votes Eutyches, who had been condemned for heresy, and restored to him the dignity which your holiness had taken away from him as unworthy of it, and like the strangest of wild beasts, falling upon the vine which he found in the finest condition, He uprooted it and brought in that which had been cast away as unfruitful, and those who acted like true shepherds he cut off, and set over the flocks those who had shown themselves wolves: and besides all this he stretched forth his fury even against him who had been charged with the custody of the vine by the Savior, we mean of course your holiness, and purposed excommunication against one who had at heart the unifying of the Church. And instead of showing penitence for this, instead of begging mercy with tears, he exulted as if over virtuous actions, rejecting your holiness’ letter and resisting all the dogmas of the Truth.
And we ought to have left him in the position where he had placed himself: but, since we profess the teaching of the Savior “who wishes all men to be saved and to come to a knowledge of the Truth,” as a fact we took pains to carry out this merciful policy towards him, and called him in brotherly fashion to judgment, not as if trying to cut him off but affording him room for defense and healing; and we prayed that he might be victorious over the many charges they had brought against him, in order that we might conclude our meeting in peace and happiness and Satan might gum no advantage over us. But he, being absolutely convicted by his own conscience, by shirking the trial gave countenance to the accusations and rejected the three lawful summonses he received. In consequence of which, we ratified with such moderation as we could the vote which he had passed against himself by his blunders, stripping the wolf of his shepherd’s skin, which he had long been convicted of wearing for a pretense. Thereupon our troubles ceased and straightway a time of welcome happiness set in: and having pulled up one tare, we filled the whole world to our delight with pure grain: and having received, as it were, full power to root up and to plant, we limited the up-rooting to one and carefully plant a crop of good fruit. For it was God who worked, and the triumphant Euphemia who crowned the meeting as for a bridal, and who, taking our definition of the faith as her own confession, presented it to her Bridegroom by our most pious Emperor and Christ-loving Empress, appeasing all the tumult of opponents and establishing our confession of the truth as acceptable to Him, and with hand and tongue setting her seals to the votes of us all in proclamation thereof. These are the things we have done, with you present in the spirit and known to approve of us as brethren, and all but visible to us through the wisdom of your representatives.
And we further inform you that we have decided on other things also for the good management and stability of church matters, being persuaded that your holiness will accept and ratify them, when you are told. The long prevailing custom, which the holy Church of God at Constantinople had of ordaining metropolitans for the provinces of Asia, Pontus and Thrace, we have now ratified by the votes of the Synod, not so much by way of conferring a privilege on the See of Constantinople as to provide for the good government of those cities, because of the frequent disorders that arise on the death of their bishops, both clergy and laity being then without a leader and disturbing church order. And this has not escaped your holiness, particularly in the case of Ephesus, which has often caused you annoyance.
We have ratified also the canon of the 150 holy Fathers who met at Constantinople in the time of the great Theodosius of holy memory, which ordains that after your most holy and Apostolic See, the See of Constantinople shall take precedence, being placed second: for we are persuaded that with your usual care for others you have often extended that Apostolic prestige which belongs to you, to the church in Constantinople also, by virtue of your great disinterestedness in sharing all your own good things with your spiritual kinsfolk.
Accordingly vouchsafe most holy and blessed father to accept as your own wish, and as conducing to good government the things which we have resolved on for the removal of al confusion and the confirmation of church order. For your holiness’ delegates, the most pious bishops Paschasinus and Lucentius, and with them the right Godly presbyter Boniface, attempted vehemently to resist these decisions, from a strong desire that this good work also should start from your foresight, in order that the establishment of good order as well as of the Faith should be put to your account.
For we duly regarding our most devout and Christ loving Emperors, who delight therein, and the illustrious senate and, so to say, the whole imperial city, considered it opportune to use the meeting of this ecumenical Synod for the ratification of your honor, and confidently corroborated this decision as if it were initiated by you with your customary fostering zeal, knowing that every success of the children rebounds to the parent’s glory.
Accordingly, we entreat you, honor our decision by your assent, and as we have yielded to the head our agreement on things honorable, so may the head also fulfill for the children what is fitting. For thus will our pious Emperors be treated with due regard, who have ratified your holiness’ judgment as law, and the See of Constantinople will receive its recompense for having always displayed such loyalty on matters of religion towards you, and for having so zealously linked itself to you in full agreement. But that you may know that we have done nothing for favor or in hatred, but as being guided by the Divine Will, we have made known to you the whole scope of our proceedings to strengthen our position and to ratify and establish what we have done.
LETTER 101: FROM ANATOLIOS OF CONSTANTINOPLE TO LEO OF ROME
Since after passing judgment upon him we had to come to an agreement with prayers and tears upon a definition of the right faith; for that was the chief reason for the Emperor’s summoning the holy Synod, at which your holiness was present in the spirit with us, and wrought with us by the God-fearing men who were sent from you; we, having the protection of the most holy and beautiful martyr Euphemia, have all given ourselves to this important matter with all deliberateness. And as the occasion demanded that all the assembled holy bishops should publish a unanimous decision for clearness and for an explicit statement of the faith in our Lord Jesus Chris, our Lord God who is found and revealed even to those who seek Him not, yes, even to those who ask not for Him, in spite of some attempts to resist at first, nevertheless showed us His truth, and ordained that it should be written down and proclaimed by all unanimously and without gainsaying, which thus confirmed the souls of the strong, and invited into the way of truth all who were swerving therefrom. And, indeed, after unanimously setting our names to this document, we who have assembled in this ecumenical Synod in the name of the faith of the same most holy and triumphant martyr, Euphemia, and of our most pious and Christ-loving Emperor Marcian, and our most pious and in all things most faithful daughter the Empress Pulcheria Augusta, with prayer and joy and happiness, having laid on the holy altar the definition written in accordance with your holy epistle for the confirmation of our Fathers’ faith, presented it to their pious care; for thus they had asked to receive it, and, having received it, they glorified with us their Master Christ, who had driven away all the mist of heresy and had graciously made clear the word of truth. And in this way was simultaneously established the peace of the Church and the agreement of the priests concerning the pure faith by the Savior’s mercy.