In the confusion of the fifth century, when the provinces of the Roman Empire were being lopped off one by one, Italy invaded, and the larger political institutions disappearing, the Church was the one institution that maintained itself. In not a few places among the barbarians the bishops became the acknowledged heads of the Roman element of the communities. In meeting the threatened invasion of Italy by Attila, Leo was the representative of the Roman people, the head of the embassy sent to induce the Hun to recross the Danube. Under such circumstances the see of Rome constantly gained in importance politically and ecclesiastically. As a centre of unity it was far more powerful than a feeble emperor at Ravenna or puppets set up by barbarians. It was the one and only great link between the provinces and the representative of the ancient order. It represented Rome, an efficient and generally gratefully recognized authority. In the development of the papal idea the first stadium was completed with the pontificate of Leo the Great (440-461), who, fully conscious of the inherited Petrine prerogatives, expressed them the most clearly, persistently, and, on the whole, most successfully of any pontiff before Gregory the Great. Leo, therefore, stands at the end of a development marked by the utterances of Victor, Cornelius, Siricius, Innocent I, Zosimus, Boniface I, and Celestine. For their statements of the authority of the Roman see, see Denziger, under their names, also Kirch and Mirbt. The whole may be found combined in one statement in Schwanne, Dogmengeschichte, I, 413 f.; II, 661-698.
Additional source material: In English there is comparatively little except the writings of Leo, see especially Sermones 2, 82, 84; Epistulæ 4, 6, 10, 12, 13, 14, 17, 105, 167; Jerome, Ep. 146, ad Evangelum. Kirch, Mirbt, and Denziger give many references to original texts and citations.
(a) Leo the Great, Sermo 3. (MSL, 55:145 f.)
On the prerogatives of Peter and his see.
Ch. 2. … From His overruling and eternal providence we have received also the support of the Apostle's aid, which assuredly does not cease from its operation; and the strength of the foundation, on which the whole lofty building of the Church is reared, is not weakened by the weight of the temple that rests upon it. For the solidity of that faith which was praised in the chief of the Apostles is perpetual; and, as that remains which Peter believed in Christ, so that remains which Christ instituted in Peter. For when, as has been read in the Gospel lesson [i.e., for the day], the Lord has asked the disciples whom they believed Him to be, amid the various opinions that were held, the blessed Peter replied, saying: “Thou art the Christ,” etc. [Matt. 16:16-19].
Ch. 3. The dispensation of the truth therefore abides, and the blessed Peter, persevering in the strength of the rock which he has received, has not abandoned the helm of the Church which he undertook. For he was ordained before the rest in such a way that since he is called the rock, since he is pronounced the foundation, since he is constituted the doorkeeper of the kingdom of heaven, since he is set up as the judge to bind and to loose, whose judgments shall retain their validity in heaven, from all these mystical titles we might know the nature of his association with Christ. And still to-day he more fully and effectually performs what is intrusted to him, and carries out every part of his duty and charge in Him and with Him, through whom he has been glorified. And so if anything is rightly done or rightly decreed by us, if anything is obtained from the mercy of God by daily supplications, it is his work and merits whose power [pg 478] lives in his see and whose authority excels. For this, dearly beloved, that confession gained, that confession which, inspired in the Apostle's heart by God the Father, transcends all the uncertainty of human opinions, and was endued with the firmness of a rock, which no assaults could shake. For throughout the Church Peter daily says, “Thou art the Christ, the Son of the living God,” and every tongue which confesses the Lord is inspired by the instruction [magisterio] of that voice.
(b) Leo the Great, Ep. 104, ad Marcianum Augustum, A. D. 452. (MSL, 54:993.)
Condemnation of the twenty-eighth canon of Chalcedon.
This and the two following epistles upon the twenty-eighth canon of the Council of Chalcedon define the relation of the Roman see to councils, canons, and patriarchal sees. Apostolic sees may not be constituted by mere canon; political importance of a place does not regulate its ecclesiastical position; the see of Rome can reject the canons of councils even though general; apostolic sees connected with Peter may not have their authority diminished. For the twenty-eighth canon of Chalcedon, v. infra, [§ 90, d].
Ch. 3. Let the city of Constantinople have, as we desire, its glory, and may it, under the protection of God's right hand, long enjoy the rule of your clemency. Yet the basis of things secular is one, and the basis of things divine another; and there can be no sure building save on that rock which the Lord laid as a foundation. He that covets what is not his due, loses what is his own. Let it be enough for the aforesaid [Anatolius, bishop of Constantinople] that by the aid of your piety and by my favorable assent he has obtained the bishopric of so great a city. Let him not disdain a royal city, which he cannot make an apostolic see; and let him on no account hope to be able to rise by injury to others. For the privileges of the churches, determined by the canons of the holy Fathers, and fixed by the decrees of the Nicene synod, cannot be overthrown by an unscrupulous act, nor disturbed by an innovation. And in the faithful execution of this task by the aid of Christ, it is necessary that I show an unflinching devotion; [pg 479] for it is a charge intrusted to me, and it tends to condemnation if the rules sanctioned by the Fathers and laid down under the guidance of God's spirit at the synod of Nicæa for the government of the whole Church are violated with my connivance (which God forbid) and if the wishes of a single brother have more weight with me than the common word of the Lord's whole house.