Warning: A non-numeric value encountered in /home/web2cowi/public_html/wp-content/themes/astra/inc/class-astra-dynamic-css.php on line 3458
Leo I The Great (C. 400-461) - Coptic Wiki

LEO I THE GREAT (c. 400-461)

The pope who asserted uncompromisingly the primacy of the papacy, opposing both the doctrinal and ecclesiastical claims of Alexandria, represented by the patriarch DIOSCORUS I. He also helped to defend Rome against threatened attack by the Huns. He is regarded as a doctor of the church and saint in the Roman Catholic church (feast day: 10 Nov.) and as a saint in the Orthodox church (feast day: 18 Feb.).

Leo was an Italian, if not a Roman, by birth. Perhaps he is to be identified with the “acolyte Leo” who brought letters from the deacon Sixtus (afterward Pope Sixtus III) to Aurelius, Augustine, and other African bishops in 418 (Augustine, Letters 191, 194.1). If so, his date of birth would be about 395. Under Pope Celestine I he was deacon and, according to Gennadius (De viris illustribus 61), he was archdeacon of Rome. In the doctrinal struggle between CYRIL I, patriarch of Alexandria, and NESTORIUS on the nature of Christ, he was on the anti-Nestorian side, according to Cassian (De incarnatione, praefatio) and the recipient of a letter from Cyril urging him not to sanction the promotion of Juvenal of Jerusalem to patriarchal status. This is his first recorded contact with Alexandria, and it was a friendly one.

Leo continued to be influential during the pontificate of Sixtus III, and in 439 Prosper Tiro records in his Chronicon his warning against readmitting former Bishop Julian of Eclanum to the church, on the grounds that he had not recanted his Pelagian errors. In 440 Leo was head of a diplomatic mission to Gaul, to heal the breach between the general Aetius and the pretorian prefect Albinus, when Sixtus died in mid-August. The Roman church waited for him to return to consecrate him pope on 29 September 440.

The first five years of Leo’s pontificate were occupied mainly with problems of the church in Rome and the West. His early letters and sermons denounce the heretical views of Manichees, Priscillianists, and Pelagius (see PELAGIANISM). In these works he makes it clear that he regards himself, as bishop of Rome, to be a mouthpiece of Peter. It was this “power that lives and his authority that prevails in his See” (Sermon 3.3). In 445, the Western emperor, Valentinian III, pronounced that in the provinces under his rule, “whatever the authority of the Apostolic See has enacted, or may hereafter enact, shall be the law for all.” Bishops summoned for trial before the bishop of Rome would be compelled to attend. Though Valentinian’s edict was aimed at settling a dispute between Hilary, bishop of Arles, and the pope, it set a precedent for papal supremacy in the Western church throughout the Middle Ages.

The position of the papacy in the East, however, was to be vastly different. Dioscorus I succeeded his uncle, Cyril, as patriarch of Alexandria in June 444. The first contacts between him and Leo were friendly enough, with Leo offering some well-meant if patronizing advice, as if counseling an inexperienced subordinate. He told Dioscorus that he should not hesitate to celebrate the liturgy twice on the same day if necessary, and gave instructions on how to ordain clergy according to the proper procedure. Leo was not the only bishop of that time to misjudge Dioscorus.

Leo does not appear to have had an agent in the imperial capital, Constantinople, and the ever-increasing complications of the dispute between Flavian, patriarch of Constantinople, and the monophysite- minded archimandrite EUTYCHES passed him by. When the crisis erupted in the winter and spring of 448-449, he was on the sidelines and surprised at the fuss. Eutyches had written to him in 448 deploring the revival of “Nestorianism,” and Leo had replied on 1 June, thanking him for his solicitude. After his condemnation by the synod at Constantinople on 22 November, Eutyches had included Leo among the senior ecclesiastics to whom he appealed against his sentence. Breakdowns in communication between Rome and Constantinople prevented Flavian’s report of the synod’s proceedings from reaching Rome. Leo was irked by what appeared to be Flavian’s neglect and failed to give his colleague in Constantinople timely support. It was exactly a month from 13 May, when he received his summons to the “Robber Council” that the Eastern emperor had convoked at Ephesus, to his dispatch of his letter to on 12 June, affirming in uncompromising terms the of the two natures of Christ. This letter, number 28, has become known to history as the Tome of Leo.

Leo’s object was to steer between the teachings of Nestorius and of Eutyches on the basis of accepted in the West. Christ was to be recognized in two natures, the properties of each nature being present in the other (the COMMUNICATIO IDIOMATUM). Although Leo sent similar letters to the emperor’s sister, Pulcheria, and to the council via his legate, the Tome was for the time being ineffective. It arrived too late to help Flavian; and, not unreasonably, Dioscorus, who presided at the council, which opened on 8 August, considered that the emperor’s letters and the issue between and Eutyches should be judged first. The Tome was not refused a reading but was placed far down the agenda. Before it was reached, Eutyches had been acquitted of heresy, and had been condemned for disturbing the good order of the church and seeking to add to the Nicene Creed (by teaching the recognition of two natures in Christ). He was declared deposed. The papal legate, the deacon Hilarius (later pope), and Julius, bishop of Puteoli, were grossly insulted. It was perhaps fortunate that the Tome had not been read, for the prevailing mood of the council would have led to its condemnation and its author’s excommunication.

So long as Emperor Theodosius II lived, Alexandria was the “city of the orthodox,” and a interpretation of Cyril’s theology was the faith accepted by Eastern Christendom. In Flavian’s place was Dioscorus’ trusted deacon and representative in the capital, Anatolius. Despite great activity and many expostulations, there was little that Leo could do to alter matters. On 28 July 450, however, Theodosius died as the result of a hunting accident. Everything changed overnight. The new ruler, Pulcheria, and the elderly Thracian officer Marcian, whom she married on 25 August, were intent on restoring relations between Constantinople and Rome. In the ensuing months Leo was brought round to the idea of a new council, and Anatolius was weaned from his dependence on Dioscorus. On 23 May 451, Pulcheria and Marcian summoned an ecumenical council to meet at NICAEA in September. The location was changed to CHALCEDON and the date changed to 8 October, but the terms of reference suited Leo. The new council was “to end the disputations and settle the true faith more clearly and for all time.”

Leo had had last-minute hesitations before accepting the emperor’s invitation. In the event, the council had elements both of triumph and of setback for him and the Roman see. The Tome was accepted as orthodox. Leo’s formulation that “two natures are united without change, without division and without confusion in Christ” found its place in the final Christological definition; but his legates failed to prevent the council from agreeing with Canon 28, which placed Constantinople on a par with the Roman see except for the “primacy of honor” reserved to the latter. Also, the Tome was accepted only because the bishops, in their willingness to please the and their readiness to rid themselves of Dioscorus, were prepared to affirm with acclamation that “Cyril and Leo taught alike.” The priority, however, was Cyril’s.

For the remainder of his pontificate, Leo was occupied in long, drawn-out disputes with the imperial court and Eastern that were designed to safeguard the Chalcedonian definition from all attempts to reinterpret it or undermine its authority, and at the same time to deny the validity of Canon 28 of the council. Thus, in March 453, Leo branded those who questioned the binding character of the definition as “Eutychians” and heretics. On 21 June 453, in response to Marcian’s request to him, as “ of Rome,” that he ratify all the decrees of the council, Leo stated his reservations regarding Canon 28. Previously he had told Anatolius that while Constantinople might be a royal city, nothing could make it into an apostolic see, and this remained his position.

Marcian died on 26 January 457, and his successor, Emperor Leo I, respected the decisions of Chalcedon. However, supporters of Dioscorus (who had died in 454) consecrated a former presbyter of Cyril’s, TIMOTHY II “the Cat,” as patriarch (16 March). Twelve days later his rival, Proterius, who had been appointed at the Council of Chalcedon and was loyal to its decrees, was murdered (Maundy Thursday, 28 March).

The events that followed led to a culmination of Leo’s difficulties in the East. Despite his protests, he had not been able to prevent Anatolius from “promoting” the deacon Aetius, who had been secretary at the Council of Chalcedon, to the rank of presbyter in charge of unpleasant duties connected with the cemeteries of the capital. Nor, in the same year (453), had he kept Anatolius from consecrating the patriarch of Antioch and hence demonstrating his position as senior bishop in the East. In July 453, the death of Pulcheria had robbed Leo of an important supporter in Constantinople. Now, he failed to have the murderers of Proterius punished. Despite frantic activity in important and well-argued letters, dispatched on 1 September 457, the future of Timothy was decided by the emperor and the bishops of the East. A “plebiscite” involving some 1,600 bishops came out overwhelmingly against Timothy in early 458 and vindicated Chalcedon’s value at least as a disciplinary council that also formally protected the rights of the see of Constantinople against all comers.

In 458 and 459, Leo attempted to justify the papal attitude toward Chalcedon. The emperor forwarded Leo’s letters to Timothy, whose reply that he was prepared to condemn Eutyches, as well as the Tome of Leo and the Council of Chalcedon, defined the attitude of the anti-Chalcedonian (later, and Coptic) church in Alexandria from thenceforth (Zacharias Rhetor ecclesiastica 4.6). The emperor was, however, dissatisfied with Timothy’s reply, and he had Timothy arrested and removed from Alexandria at the end of 459. Leo had the satisfaction of seeing the line of Chalcedonian patriarchs continued in Alexandria by TIMOTHY SALOFACIOLUS (“little white turban”) in the spring of 460. He showed some independence from Rome, and one of Leo’s last acts was to protest the inclusion of Dioscorus on the diptychs containing the names of those to be remembered at the celebration of the in his church. His last recorded letters, sent on 22 August 461, were also to Timothy. He died on 10 November of that year.

Leo’s life and achievement must be assessed against his actions in both the West and the East. In the West he enabled the papacy to emerge as the one authoritative and stabilizing force in a period of crisis and confusion resulting from the invasion of Attila the Hun and constant movements of the Germanic peoples in the former provinces of the Western empire.

In the East, however, he was less successful, and his effect on the Coptic church was wholly negative. Anti-Chalcedonian (and later, monophysite) opinion was not alienated from the Roman see as such; Pope I was believed by SEVERUS OF ANTIOCH, on the strength of Apollinarian forgeries, to have favored the “one nature” Christology. The Tome of Leo, however, was associated with the Council of Chalcedon as an impious and heretical document. “Cursed be the Council. Cursed be the Tome of Leo”— the outcries of the populace of Antioch at the time of Severus’ enthronement as patriarch on 6 November 518 (John of Beit- Aphthonia, Life of Severus, p. 111)—were typical of reactions in the East. In Egypt, condemnation of the Tome figured, with the abrogation of Chalcedon, as the basic requirement in every negotiation between the Coptic- church and the imperial authority. For the Coptic church Leo and Cyril did not teach alike, and no one has convinced its adherents that they did.


  • Batiffol, P. “Léon Grand.” In Dictionnaire de théologie catholique, Vol. 9, pp. 218-301. Paris, 1926.
  • Dvornik, F. Byzance et la primauté romaine. Paris, 1964.
  • Frend, W. H. C. “Eastern Attitudes to Rome During the Acacian Schism.” In Studies in Church History, ed. D. Baker, Vol. 13, pp. 69-81. Oxford, 1976.
  • Hofmann, P. “Der Kampf der Päpste um Konzil und Dogma von Chalkedon von Leo dem Grossen bis Hormisdas (451-519).” In Das Konzil von Chalkedon, ed. A. Grillmeier und H. Bacht, Vol. 2, pp. 13-94. Würzburg, 1953.
  • Jalland, T. G. The Life and Times of St. Leo the Great. London, 1941.
  • Pickman, E. M. The Mind of Latin Christendom, pp. 589-616. London, 1937.