Pope Leo I

Pope Saint Leo I (c. 400 – 10 November 461), also known as Saint Leo the Great, was pope from 29 September 440 to his death in 461.
He was an Italian aristocrat, and was the first pope to have been called "the Great". He is perhaps best known for having met Attila the Hun in 452 and persuading him to turn back from his invasion of Italy. He is also a Doctor of the Church, most remembered theologically for issuing the Tome of Leo, a document which was a major foundation to the debates of the Ecumenical Council of Chalcedon. The Council of Chalcedon, the fourth ecumenical council, dealt primarily with Christology, and elucidated the orthodox definition of Christ's being as the hypostatic union of two natures, divine and human, united in one person, "with neither confusion nor division". It was followed by a major schism associated with Monophysitism, Miaphysitism and Dyophysitism.

According to the Liber Pontificalis, he was a native of Tuscany. By 431, as a deacon, he occupied a sufficiently important position for Cyril of Alexandria to apply to him in order that Rome's influence should be thrown against the claims of Juvenal of Jerusalem to patriarchal jurisdiction over Palestine unless the letter is addressed rather to Pope Celestine I. About the same time John Cassian dedicated to him the treatise against Nestorius written at his request. Near the end of the reign of Pope Sixtus III, Leo was dispatched at the request of Emperor Valentinian III to settle a dispute between Aëtius, one of Gaul's chief military commanders, and the chief magistrate Caecina Decius Aginatius Albinus. These two men were the two highest officials in Gaul. Leo's work helped to solidify political and religious unity in his area of the Roman Empire.

During his absence on this mission, Pope Sixtus III died (11 August 440), and Leo was unanimously elected by the people to succeed him. On 29 September, he entered upon a pontificate that was to be epoch-making for the centralisation of the government of the Roman Church.

Teaching on Christ

Leo's writings (both the sermons and the letters) are mostly concerned with theological questions concerning the person of Jesus Christ (Christology) and his role as mediator and savior (Soteriology), which is partially connected to the Council of Chalcedon in which Roman legates participated in Leo's name. Subsequently, through numerous letters addressed to bishops and members of the imperial family, Leo incessantly worked for the propagation and universal reception of the faith in Christ as defined by Chalcedon, also in the eastern part of the Roman empire. Leo defends the true divinity and the true humanity of the one Christ against heretical one-sidedness. He takes up this topic also in many of his sermons, and over the years, he further develops his own original concepts. A central idea around which Leo deepens and explains his theology is Christ's presence in the Church, more specifically in the teaching and preaching of the faith (Scripture, Tradition and their interpretation), in the liturgy (sacraments and celebrations), in the life of the individual believer and of the organized Church, especially in a council.

To Leo the Great, Mariology is determined by Christology. If Christ were divine only, everything about him would be divine. Only his divinity would have been crucified, buried and resurrected. Mary would only be the mother of God, and Christians would have no hope for their own resurrection. The nucleus of Christianity would be destroyed. The most unusual beginning of a truly human life through her was to give birth to Jesus, the Lord and Son of King David.

Apostle Peter and his heir

Leo contributed to the development of the doctrine on papal primacy, based on his personal devotion to St Peter and on the veneration for the Apostle and his tomb in Rome. Besides recourse to biblical language, Leo also describes his own special relationship with St Peter in terms derived from Roman law. He calls himself the (unworthy) heir and deputy (vicarius) of Peter, having received his apostolic authority and being obliged to follow his example. On the one hand, Peter stands before him with a claim on how Leo is to exercise his office; on the other hand, Leo, as the Roman bishop, represents the Apostle, whose authority he holds. Christ, however, always comes out as the source of all grace and authority, and Leo is responsible to him for how he fulfills his duties (sermon 1). Peter is indeed the example for Leo's relationship to Christ. Thus, the office of the Roman bishop, with its universal significance, is grounded on the special relationship between Christ and St Peter, a relationship that cannot be repeated per se; therefore, Leo depends on St Peter's mediation, his assistance and his example in order to be able to adequately fulfill his role and exercise his authority as the Bishop of Rome, both in the city and beyond.

Decree of Valentinian

Priest celebrating Mass at Altar of Leo the Great in St. Peter's Basilica

Leo was a significant contributor to the centralisation of spiritual authority within the Church and in reaffirming papal authority. The bishop of Rome had gradually become viewed as the chief patriarch in the Western church. Leo would push that authority into a new realm. With serious opposition, he asserted his authority in Gaul. Patroclus of Arles (d. 426) had received from Pope Zosimus the recognition of a subordinate primacy over the Gallican Church which was strongly asserted by his successor Hilary of Arles. An appeal from Chelidonius of Besançon gave Leo the opportunity to assert the pope's authority over Hilary, who defended himself stoutly at Rome, refusing to recognize Leo's judicial status. Feeling that the primatial rights of the bishop of Rome were threatened, Leo appealed to the civil power for support and obtained, from Valentinian III, the famous decree of 6 June 445, which recognized the primacy of the bishop of Rome based on the merits of Peter, the dignity of the city, and the legislation of the First Council of Nicaea; and provided for the forcible extradition by provincial governors of any bishop who refused to answer a summons to Rome. Faced with this decree, Hilary submitted to the pope, although under his successor, Ravennius, Leo divided the metropolitan rights between Arles and Vienne (450).

Dispute with Dioscorus of Alexandria

In 445, Leo disputed with Patriarch Dioscorus, St Cyril's successor as Patriarch of Alexandria, insisting that the ecclesiastical practice of his see should follow that of Rome on the basis that Mark the Evangelist, the disciple of St Peter and the founder of the Alexandrian Church, could have had no other tradition than that of the prince of the apostles.

Other regions

Regarding Africa, the fact that the African province of Mauretania Caesariensis had been preserved to the empire and thus to the Nicene faith during the Vandal invasion and, in its isolation, was disposed to rest on outside support, gave Leo an opportunity to assert his authority there, which he did decisively in regard to a number of questions of discipline.

Regarding Italy, in a letter to the bishops of Campania, Picenum, and Tuscany (443) he required the observance of all his precepts and those of his predecessors; and he sharply rebuked the bishops of Sicily (447) for their deviation from the Roman custom as to the time of baptism, requiring them to send delegates to the Roman synod to learn the proper practice.

Regarding Greece, because of the earlier line of division between the western and eastern parts of the Roman Empire, Illyria was ecclesiastically subject to Rome. Pope Innocent I had constituted the metropolitan of Thessalonica his vicar, in order to oppose the growing influence of the patriarch of Constantinople in the area. In a letter of about 446 to a successor bishop of Thessalonica, Anastasius, Leo reproached him for the way he had treated one of the metropolitan bishops subject to him; after giving various instructions about the functions entrusted to Anastasius and stressing that certain powers were reserved to the pope himself, Leo wrote: "The care of the universal Church should converge towards Peter's one seat, and nothing anywhere should be separated from its Head."

Council of Chalcedon

A favorable occasion for extending the authority of Rome in the East was offered in the renewal of the Christological controversy by Eutyches, who in the beginning of the conflict appealed to Leo and took refuge with him on his condemnation by Flavian. But on receiving full information from Flavian, Leo took his side decisively. In 451 at the Council of Chalcedon, after Leo's Tome on the two natures of Christ was read out, the bishops participating in the Council cried out: "This is the faith of the fathers ... Peter has spoken thus through Leo ..."

An uncompromising foe of heresy, Leo found that in the almanac of Aquileia, Pelagians were received into church communion without formal repudiation of their errors; he wrote to rebuke them, making accusations of culpable negligence, and required a solemn abjuration before a synod.

Manichaeans fleeing the Vandals had come to Rome in 439 and secretly organized there; Leo learned of it around 443, and proceeded against them by holding a public debate with their representatives, burning their books and warning the Roman Christians against them.

His attitude was as decided against the Priscillianists. Bishop Turibius of Astorga, astonished at the spread of the sect in Spain, had addressed the other Spanish bishops on the subject, sending a copy of his letter to Leo, who took the opportunity to exercise Roman policy in Spain. He wrote an extended treatise (21 July 447) against the sect, examining its false teaching in detail and calling for a Spanish general council to investigate whether it had any adherents in the episcopate, but that was prevented by the political circumstances of Spain.

At the Second Council of Ephesus in 449, Leo's representatives delivered his famous Tome, a statement of the faith of the Roman Church in the form of a letter addressed to Archbishop Flavian of Constantinople, which repeats, in close adherence to Augustine of Hippo, the formulas of western Christology. The council did not read the letter and or pay any attention to the protests of Leo's legates but deposed Flavian and Eusebius of Dorylaeum, who appealed to Rome. That is one reason that the council was never recognized as ecumenical and was later repudiated by the Council of Chalcedon.

It was presented again at the subsequent Council of Chalcedon as offering a solution to the Christological controversies still raging between East and West. This time, it was read out. The acts of the council report: "After the reading of the foregoing epistle, the most reverend bishops cried out: This is the faith of the fathers, this is the faith of the Apostles. So we all believe, thus the orthodox believe. Anathema to him who does not thus believe. Peter has spoken thus through Leo. So taught the Apostles. Piously and truly did Leo teach, so taught Cyril. Everlasting be the memory of Cyril. Leo and Cyril taught the same thing, anathema to him who does not so believe. This is the true faith. Those of us who are orthodox thus believe. This is the faith of the fathers. Why were not these things read at Ephesus? These are the things Dioscorus hid away."

Leo demanded of the emperor that an ecumenical council should be held in Italy, and in the meantime, at a Roman synod in October 449, repudiated all the decisions of the "Robber Synod". Without going into a critical examination of its dogmatic decrees, in his letters to the emperor and others he demanded the deposition of Eutyches as a Manichaean and Docetic heretic.

With the death of Theodosius II in 450 and the sudden change in the Eastern situation, Anatolius, the new patriarch of Constantinople fulfilled Leo's requirements, and his Tome was everywhere read and recognized.

Leo was now no longer desirous of having a council, especially since it was not to be held in Italy. Instead, it was called to meet at Nicaea, then subsequently transferred to Chalcedon, where his legates held at least an honorary presidency, and where the bishops recognized him as the interpreter of the voice of Peter and as the head of their body, requesting of him the confirmation of their decrees.

He firmly declined to confirm their disciplinary arrangements, which seemed to allow Constantinople a practically equal authority with Rome and regarded the civil importance of a city as a determining factor in its ecclesiastical position; but he strongly supported its dogmatic decrees, especially when, after the accession of Leo I the Thracian (457), there seemed to be a disposition toward compromise with the Eutychians.

He succeeded in having an imperial patriarch, and not the Oriental Orthodox Pope Timotheus Aelurus, chosen as Coptic Orthodox Pope of Alexandria on the murder of Greek Patriarch Proterius of Alexandria.

The approaching collapse of the Western Empire gave Leo a further opportunity to appear as the representative of lawful authority.

Raphael's The Meeting between Leo the Great and Attila depicts Leo, escorted by Saint Peter and Saint Paul, meeting with the Hun king outside Rome.

Despite his defeat at the Battle of Chalons in 451, Attila invaded Italy in 452, sacking cities such as Aquileia and heading for Rome. He allegedly demanded that the sister of the reigning Emperor Valentinian III be sent to him with a dowry. In response, the emperor sent three envoys to negotiate with Attila: Gennadius Avienus, one of the consuls of 450, Memmius Aemilius Trygetius, the former urban prefect, and Leo. Little is known of the specifics of the negotiations, as a result of which Attila withdrew. Most ancient and medieval historians celebrated Leo's actions, giving him all the credit for this successful embassy. According to Prosper of Aquitaine who was alive at the time of the event, Attila was so impressed by Leo that he withdrew. Another near-contemporary was the historian Priscus who records that Attila was dissuaded from attacking Rome by his own men because they feared he would share the fate of the Visigothic king Alaric, who died shortly after sacking the city in 410. Paul the Deacon, in the late 8th century, relates that an enormously huge man dressed in priestly robes and armed with a naked sword, visible only to Attila, threatened him and his army with death during his discourse with Leo, and this prompted Attila to submit to his request.

More modern historians debate other possible reasons for Attila's sudden withdrawal. The pope may have offered Attila a large sum of gold or Attila may have had logistical and strategic concerns: an army probably laden with booty from plunder; a plague in northern Italy; food shortages; military actions of the Eastern Emperor Marcianus on the Danube frontier. Besides, the whereabouts of Aëtius at that time are unknown, and Attila or his warriors may have felt endangered by their arch-enemy from the Catalaunian plains.

Writing in the early 20th century, John B. Bury remarked:

The fact of the embassy cannot be doubted. The distinguished ambassadors visited the Hun's camp near the south shore of Lake Garda. It is also certain that Attila suddenly retreated. But we are at a loss to know what considerations were offered him to induce him to depart. It is unreasonable to suppose that this heathen king would have cared for the thunders or persuasions of the Church. The Emperor refused to surrender Honoria, and it is not recorded that money was paid. A trustworthy chronicle hands down another account which does not conflict with the fact that an embassy was sent, but evidently furnishes the true reasons which moved Attila to receive it favourably. Plague broke out in the barbarian host and their food ran short, and at the same time troops arrived from the east, sent by Marcian to the aid of Italy. If his host was suffering from pestilence, and if troops arrived from the east, we can understand that Attila was forced to withdraw. But whatever terms were arranged, he did not pretend that they meant a permanent peace. The question of Honoria was left unsettled, and he threatened that he would come again and do worse things in Italy unless she were given up with the due portion of the Imperial possessions.

Leo's intercession could not prevent the sack of the city by the Vandals in 455, but murder and arson were repressed by his influence. Leo did, however, assist in rebuilding the city of Rome; restoring key places such as Saint Peter's. He died in 461 and, as he wished to be buried as close as possible to the tomb of St Peter, his body was placed in a tomb in the portico of Saint Peter's basilica on 10 November of that year and in 688 was moved inside the basilica itself.

In his In Nativitate Domini, Christmas Day, sermon, "Christian, remember your dignity", Leo articulates a fundamental dignity common to all Christians, whether saints or sinners, and the consequent obligation to live up to it:

Our Saviour, dearly-beloved, was born today: let us be glad. For there is no proper place for sadness, when we keep the birthday of the Life, which destroys the fear of mortality and brings to us the joy of promised eternity. No one is kept from sharing in this happiness. There is for all one common measure of joy, because as our Lord the destroyer of sin and death finds none free from charge, so is He come to free us all. Let the saint exult in that he draws near to victory. Let the sinner be glad in that he is invited to pardon. Let the gentile take courage in that he is called to life...

Let us put off then the old man with his deeds: and having obtained a share in the birth of Christ let us renounce the works of the flesh. Christian, acknowledge thy dignity, and becoming a partner in the Divine nature, refuse to return to the old baseness by degenerate conduct. Remember the Head and the Body of which thou art a member. Recollect that thou wert rescued from the power of darkness and brought out into God’s light and kingdom. By the mystery of Baptism thou wert made the temple of the Holy Ghost: do not put such a denizen to flight from thee by base acts, and subject thyself once more to the devil’s thraldom: because thy purchase money is the blood of Christ, because He shall judge thee in truth Who ransomed thee in mercy, who with the Father and the Holy Spirit reigns for ever and ever. Amen.

The significance of Leo's pontificate lies in his assertion of the universal jurisdiction of the Roman bishop, as expressed in his letters, and still more in his 96 extant orations. This assertion is commonly referred to as the doctrine of Petrine supremacy.

According to Leo and several Church Fathers as well as certain interpretations of the Scriptures, the Church is built upon Peter, in pursuance of the promise of Matthew 16:16–19. Peter participates in everything which is Christ's; what the other apostles have in common with him they have through him. What is true of Peter is true also of his successors. Every other bishop is charged with the care of his particular flock, the Roman pontiff with that of the whole Church. Other bishops are his assistants in this great task. In Leo's eyes the decrees of the Council of Chalcedon acquired their validity from his confirmation.

Leo's letters and sermons reflect the many aspects of his career and personality and are invaluable historical sources. His rhythmic prose style, called cursus leonicus, influenced ecclesiastical language for centuries.

The Roman Catholic Church marks 10 November as the feast day of Saint Leo, given in the Martyrologium Hieronymianum and the 8th-century Calendar of Saint Willibrord as the date of his death and entry to heaven. His feast was once celebrated in Rome on 28 June, the anniversary of the placing of his relics in Saint Peter's Basilica, but in the 12th century, the Gallican Rite feast of 11 April was admitted to the General Roman Calendar, which maintained that date until 1969. Some traditionalist Catholics continue to observe pre-1970 versions of that calendar.

The Eastern Catholic Churches as well as the Eastern Orthodox Church celebrate Saint Leo on 18 February.

Leo was originally buried in his own monument. However, some years after his death, his remains were put into a tomb that contained the first four Pope Leos. In the 18th century, Leo the Great's relics were separated from those of the other Leos and he was given his own chapel.

Troparion (Tone 3)

You were the Church's instrument

in strengthening the teaching of true doctrine;

you shone forth from the West like a sun dispelling the errors of the heretics.

Righteous Leo, entreat Christ God to grant us His great mercy.

Troparion (Tone 8)

O Champion of Orthodoxy, and teacher of holiness,

The enlightenment of the universe and the inspired glory of true believers.

O most wise Father Leo, your teachings are as music of the Holy Spirit for us!

Pray that Christ our God may save our souls!

Kontakion (Tone 3)

Seated upon the throne of the priesthood, glorious Leo,

you shut the mouths of the spiritual lions.

With divinely inspired teachings of the honored Trinity,

you shed the light of the knowledge of God up-on your flock.

Therefore, you are glorified as a divine initiate of the grace of God.