The See of Peter

The Early Church and Peter's Primacy

Letter XI, from Emperors Theodosius and Valentinian III to Aetius

Synopsis: The emperors, grounding the primacy of the Apostolic See in the merit of Saint Peter, the dignity of the city of Rome, and the authority of the holy synod, declare that the papal sentence against Hilary of Arles was valid throughout Gaul without imperial backing, and issue a perpetual decree that no bishop of any province may act against ancient custom without the authority of the Roman pontiff, whose summons is enforceable by civil governors.

Emperors Theodosius and Valentinian, Augusti, to Aetius, illustrious man, count, master of both armies, and patrician.

The Primacy of the Apostolic See Is Confirmed; The Sentence Against Hilary Was Valid Without Imperial Backing

It is certain that the sole defense of Our empire and Our rule lies in the favor of the supernal Divinity, to whose good pleasure the Christian faith and the religion We revere above all contribute. Since, therefore, the primacy of the Apostolic See has been confirmed by the merit of Saint Peter, who is the head of the episcopal crown, by the dignity of the city of Rome, and by the authority of the holy synod, no illicit presumption may dare to attempt anything beyond the authority of this See. For the peace of the churches will everywhere be maintained only when the whole world acknowledges its ruler.

These principles, which have until now been kept inviolably, Hilary of Arles — as We have learned from the faithful report of the venerable Leo, pope of Rome — has attempted to violate with contumacious daring by presuming certain illicit acts, and thereby caused the most abominable tumult to invade the churches beyond the Alps, as recent examples attest. Hilary, called bishop of Arles, without consulting the pontiff of the city of Rome, rashly usurped the judgments and ordinations of bishops; some he removed improperly, and ordained others against the protesting resistance of the citizens. Since such men were not readily accepted by those who had not chosen them, he gathered an armed band, and besieging or breaking down city walls in hostile fashion, led those who were to preach peace to their sees through war.

For these acts — committed against the majesty of the empire and the reverence owed to the Apostolic See — a definitive sentence has been issued against him and those he wrongfully ordained, after examination by the judgment of the religious man, the pope of the City. This sentence should have been valid throughout Gaul even without imperial sanction: for what is there that the authority of so great a pontiff may not lawfully do in the churches? But the logic of the case has also prompted Our own decree: that neither Hilary — whom only the lenient pontiff’s gentleness still permits to be called a bishop — nor anyone else, may be permitted to mix arms with ecclesiastical affairs or to resist the precepts of the Roman pontiff. For such audacity violates the faith and the reverence owed to Our empire.

A Perpetual Sanction: No Bishop of Any Province May Act Without the Roman Pontiff’s Authority

Nor do We suppress this alone — which is a crime of the gravest kind — but, lest even the slightest disturbance arise among the churches or religious discipline appear diminished in any point, We decree by this perpetual sanction: that neither the bishops of Gaul nor those of any other province dare to attempt anything against ancient custom without the authority of the venerable pope of the eternal City. And let this stand as law for all, for all time: whatever the authority of the Apostolic See has sanctioned or shall sanction. Any bishop summoned to the judgment of the Roman pontiff who neglects to appear shall be compelled by the governor of his province to present himself — with all the privileges preserved that Our divine ancestors bestowed upon the Roman Church.

Aetius, Our dearest father of illustrious and magnificent authority: let your magnificence ensure, by the authority of this edictal law, that the measures decreed above are observed, exacting immediately a fine of ten pounds of gold from any judge who allows Our precepts to be violated. With divine favor — may the Divinity preserve you for many years, dearest father.

Given on the eighth day before the Ides of July, at Rome, in the sixth consulship of Valentinian Augustus and the consulship of Nomus, vir clarissimus.

Source/Reference

PL 54:636

Notes / Historical Commentary

Letter XI is not a letter of Leo but an imperial constitution — the Novella of Valentinian III, issued July 6, 445, and sent to the Gallic churches together with Letter X. It is the most consequential imperial document for the question of papal primacy in the entire fifth century, and possibly in the entire patristic period. The reader who finds Letters IX and X essential to understanding how Leo articulated his own authority will find Letter XI equally essential for understanding how the imperial court received and codified that authority.

The document opens with a threefold grounding of the Apostolic See’s primacy: the merit of Saint Peter, the dignity of the city of Rome, and the authority of the holy synod. This tripartite formula is the standard fifth-century imperial language for the basis of Roman primacy, and the reader should note that Peter’s personal merit stands first — the other two grounds are presented as reinforcing a primacy whose root is apostolic, not merely civic or conciliar. The sentence that follows is equally striking: the peace of the churches will be maintained only when the whole world — universitas, not just the Church — acknowledges its ruler. This is the imperial court’s formulation of what Leo argues throughout his own letters: that the Petrine primacy is not a privilege of one church among many but a structural principle of the universal order.

The most remarkable passage in the document — remarkable because it comes from the emperors, not from Leo himself — is the sentence declaring that the papal judgment against Hilary should have been valid throughout Gaul even without imperial sanction. The rhetorical question that follows — “for what is there that the authority of so great a pontiff may not lawfully do in the churches?” — is a statement of complete papal jurisdiction. The emperors are not conferring validity on Leo’s sentence; they are acknowledging a validity that already existed and adding their own enforcement as a supplement to it. The distinction matters: if the empire were the source of the sentence’s validity, papal authority would be derivative of imperial authority. The Novella explicitly inverts that relationship. Leo’s authority in the churches is primary; the empire’s role is executive.

The perpetual sanction that follows extends this principle from the Gallic case to all provinces: no bishop anywhere may act against ancient custom without the authority of the Roman pontiff. Whatever the Apostolic See has sanctioned or shall sanction stands as law for all. Any bishop who refuses a papal summons is to be compelled by civil force to appear. This is papal jurisdiction backed by the apparatus of the Roman state — not as the origin of that jurisdiction but as its enforcement mechanism. The reader should note the phrase “ancient custom” (mos veterum): the emperors are presenting this not as an innovation but as a restoration of what has always been the rule, exactly as Leo himself consistently argues in his own letters.

The date — July 6, 445 — places this document seventeen days after the imperial rescript of June 19, 445 (Letter VIII), which had translated Leo’s Manichaean tribunal into civil law. The proximity is not coincidental. Both documents belong to the same concentrated period of engagement between Leo and the imperial court in the spring and summer of 445, and together they illustrate the same structural reality: Leo acts, the empire legislates from his action. The Novella was sent to Gaul together with Letter X, carrying Leo’s own detailed ruling on Hilary’s conduct. The bishops of Vienne thus received both documents simultaneously — Leo’s ruling as pastor and the emperor’s decree as lawgiver, both pointing to the same conclusion.