St. Leo I (ca. 400-461) was pope from 440 to 461. He strengthened the papal office and thus earned the title of father of the papacy. He played a large role in the disputes over the nature of Christ, and his views were accepted by the Council of Chalcedon.
The 5th century saw the rapid deterioration of Western civilization. At the beginning of the century the Goths entered northern Italy and in 410 under Alaric entered and sacked Rome. The Roman Empire in the following years changed from unified dominion to a divided and often warring group of local states. The growth of the Christian Church was the precise opposite of the decline of the empire. In the preceding 4 centuries the Church had not only spread over the civilized world but had also developed organizational patterns similar to those of the empire. Local cities were governed by bishops, of whom the bishop of the central city was preeminent.
Accession to Papacy
Very little is known of Leo prior to his accession to the papacy. The town of Volterra, 51 miles southeast of Pisa, claims to have been his birthplace; his actual birth seems to have been some time very near the end of the 4th century. His family, of Etruscan blood, probably moved to Rome early in his life to find greater security.
Leo was elected to the papacy without rival on Sept. 29, 440. The sermons he preached at his election and each year on its anniversary displayed not only his considerable rhetorical skill but also his own understanding of his office. In the sermon on the first anniversary of his elevation Leo said that St. Peter "rejoices in your love and welcomes the regard shown by the partners of his office for that which the Lord has appointed, finding in it proof of the united love of the whole Church which embraces Peter in Peter's see, and gives her affection as generously to his unworthy successor as to the great shepherd himself." Leo throughout his papacy demanded that all recognize in his office "Peter in Peter's see" and give to it the unique authority of the Petrine succession.
In the execution of the responsibilities of his office Leo displayed great administrative skill. This was particularly true in the West, where he dealt successfully with a variety of problems. The Vandal invasions of Africa and the fall of Carthage in 439 resulted in the presence of many African refugees in Rome and Italy, among whom were many Manichaeans. These dualists had long been active in North Africa, and Augustine himself had once been such a believer. Their activity in Italy presented Leo with a serious problem which he largely resolved with the help of the imperial government, which proclaimed an edict against the Manichaeans. This was enforced by a composite civil court. Such a partnership of Church and state was often useful to Leo.
Beyond his jurisdiction as metropolitan and provincial bishop Leo entered several local disputes, which he resolved in a manner that further extended the recognition of the universal authority of the Roman pope. In 444 an appeal was made to Leo against Hilary, Bishop of Arles. Leo decided against Hilary and prescribed the manner of episcopal elections and consecrations. Leo's letter to the Gallic bishops was supported by an imperial rescript signed by both emperors, Theodosius II of the East and Valentinian III of the West. In respect to the authority of the Roman see they ordered: "Let no one presume to undertake any illicit act contrary to the Authority of that see. For the peace of the churches will undoubtedly be preserved, if the whole body acknowledges its governor."
Leo also entered disputes farther from Rome. In Dacia and Macedonia, where the influence of the see of Constantinople was considerable, the bishop of Thessalonica had been regarded by the bishop of Rome as his vicar. In 446 Leo rebuked Anastasius of Thessalonica and ordered him to be more faithful to canonical procedures.
Nature of Christ
The central crisis of Leo's career grew out of a combination of doctrinal and political controversies in the Eastern Church. The Council of Nicaea had left unresolved the problem of the relationship between God and man in Jesus Christ; the Council had also not dealt with the importance of Constantinople in relation to the other major sees of the East. In the 5th century Alexandria took issue with Constantinople in terms of the doctrine of Christ.
Cyril, the able and aggressive bishop of Alexandria, maintained against Nestorius, the Antiochene bishop of Constantinople, that the human and divine are united in Christ; Nestorius sought to maintain the separate identity of the divine and human. The Council of Ephesus in 431 under the control of Cyril condemned Nestorianism. With Dioscurus, Cyril's successor, and Flavian, Nestorius's successor at Constantinople, the controversy broke out anew. The Alexandrine party contended that Flavian's insistence upon the integrity of the two natures in Christ (diophysitism) destroyed the unity of the person; against them it was argued that not to recognize the two natures was to proclaim a Christ of one nature (monophysitism) who was neither God nor man.
Early in the conflict Flavian appealed to Rome for support; Leo advised that the doctrines of the Fathers of the Church should be preserved. In March of 449 an imperial council called a council to meet at Ephesus in August. Flavian again appealed to Leo for support. Leo's answer of June 13, 449, is his most important work. In this Tome, as it is called, Leo set forth both his own doctrine and the claim of his office for final authority in matters of doctrine. Leo did not attempt to reach the speculative heights of Eastern theologies but rather set forth in direct and simple language what he believed to be the Catholic faith. In Christ the two natures of godhead and manhood meet in one person without confusion. "While the distinctness of both natures and substances is preserved, and both meet in one Person, lowliness is assumed by majesty, weakness by power, mortality by eternity." Thus setting forth a diophysite position, Leo also condemned Eutyches, a follower of Dioscurus.
The Second Council of Ephesus met under the control of the Alexandrine party, which prevented the reading of Leo's letter. Called Latrocinium (Robber's Council) by Leo, it restored Eutyches, deposed Flavian, and condemned diophysitism. These actions were supported by Theodosius II, the Eastern emperor.
The death of Theodosius gave the diophysite party the opportunity which Leo sought. In urging another council, Leo, however, desired only that monophysitism be repudiated and that his Tome be accepted as the statement of the Universal Church. The Council met at Chalcedon in 451, and at its second session on October 10 Leo's representatives secured the acceptance of the Tome and at the next session the condemnation of Dioscurus. While Leo wanted the Council to stop at this point, it proceeded to draw up a definition of the faith; nevertheless, the Roman forces prevailed in the drafting committee, and the definition proclaimed by the Council, the Chalcedonian Definition, was the triumph of Leo's Christology.
Leo's victory was mitigated, however, by the canons passed against the protest of the Roman delegates, for three canons dealt with the privileges of Constantinople. The twenty-eighth canon in particular recognized Constantinople as "New Rome," in second place in ecclesiastical affairs to the elder. Although the primacy of the pope was recognized, the patriarch of Constantinople was given the same privileges of honor and the right to ordain metropolitans in Asia, Pontus, and Thrace. These limitations of papal authority were not accepted by Leo, who declared the ultimacy of the canons of Nicaea. Despite his doctrinal victory and Leo's own conciliatory attitude, much of the monophysite party remained unconvinced and continued to exist, especially in Egypt.
Leo's concerns in this period were not merely political and doctrinal. In 452 Attila the Hun moved his forces into northeastern Italy. With an embassy of Roman leaders Leo visited Attila and obtained his withdrawal. The reasons for Attila's decision were complex, but the image of Leo's turning back the barbarians from Rome has caught the imagination of many. Gaiseric the Vandal advanced on Rome in 455, and on this occasion Leo, despite a meeting outside the walls of Rome, was unable to prevent the occupation and sack of Rome.
In the face of all of these distractions, Leo continued his overseeing of the Church. In 458 a series of letters took issue with the Synod of Narbonne and laid down enduring patterns in the West for the administration of penance. On Nov. 10, 461, Leo died.
Further Reading on St. Leo I
Edmund Hunt translated a selection of Leo's Letters (1957) in the "Fathers of the Church" series. William Bright's translation of the Tome is in Christology of the Later Fathers, edited by Edward Rochie Hardy and Cyril C. Richardson (1954). A thorough and complete biography of Leo is Trevor G. Jalland, The Life and Times of St. Leo the Great (1941). An older study is Charles Gore, Leo the Great (1897). R. V. Sellers, The Council of Chalcedon (1953), is a careful study of the Council in its context. The doctrinal questions are considered by J. N. D. Kelly, Early Christian Doctrines (1958; 4th ed. 1968).