There are three Petrine Sees: Rome, Alexandria (through St Mark), and Antioch. Here are ancient witnesses to the preeminence of the See of Rome:
Ignatius, who is also called Theophorus, to the Church which has obtained mercy, through the majesty of the Most High Father, and Jesus Christ, His only-begotten Son; the Church which is beloved and enlightened by the will of Him that willeth all things which are according to the love of Jesus Christ our God, which also presides in the place of the region of the Romans, worthy of God, worthy of honour, worthy of the highest happiness, worthy of praise, worthy of obtaining her every desire, worthy of being deemed holy,
and which presides over love, is named from Christ, and from the Father, which I also salute in the name of Jesus Christ, the Son of the Father: to those who are united, both according to the flesh and spirit, to every one of His commandments; who are filled inseparably with the grace of God, and are purified from every strange taint, * abundance of happiness unblameably, in Jesus Christ our God.
- Since, however, it would be very tedious, in such a volume as this, to reckon up the successions of all the Churches, we do put to confusion all those who, in whatever manner, whether by an evil self-pleasing, by vainglory, or by blindness and perverse opinion, assemble in unauthorized meetings; [we do this, I say,] by indicating that tradition derived from the apostles, of the very great, the very ancient, and universally known Church founded and organized at Rome by the two most glorious apostles, Peter and Paul; as also [by pointing out] the faith preached to men, which comes down to our time by means of the successions of the bishops. For it is a matter of necessity that every Church should agree with this Church, on account of its pre-eminent authority, that is, the faithful everywhere, inasmuch as the apostolical tradition has been preserved continuously by those [faithful men] who exist everywhere.
After such things as these, moreover, they still dare—a false bishop having been appointed for them by heretics—to set sail and to bear letters from schismatic and profane persons to the
throne of Peter, and to the chief church whence priestly unity takes its source; and not to consider that
these were the Romans whose faith was praised in the preaching of the apostle, to whom faithlessness could have no access.
You cannot then deny that you do know that
upon Peter first in the City of Rome was bestowed the Episcopal Cathedra, on which sat Peter, the Head of all the Apostles (for which reason he was called Cephas), that, in this one Cathedra, unity should be preserved by all, lest the other Apostles might claim----each for himself----separate Cathedras, so that he who should set up a second Cathedra against the unique Cathedra would already be a schismatic and a sinner. Well then, on the one Cathedra, which is the first of the Endowments, Peter was the first to sit.
And though this has been thus written, nevertheless,
for the sake of unity, blessed Peter (for whom it would have been enough if after his denial he had obtained pardon only) both deserved to be placed over all the Apostles, and alone received the keys of the Kingdom of Heaven, which he was to communicate to the rest.
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