Of the early life of Pope Leo I, and of his education, almost nothing is known, save that he was not taught the Greek tongue. He was consecrated Bishop of Rome in 440. And his wisdom of administration, as well as his wondrous defence of the Faith, and his singular success in saving Rome from utter destruction, (first when invaded by the Vandals,) raised the dignity of the Holy See to new heights in the eyes of all the world. Thus was gained for him the title of The Great, which name is shared by only two other Popes, to wit, Saints Gregory I and Nicholas I. Attila, King of the Huns, surnamed the Scourge of God, raged through Italy, pillaging, burning, and destroying, and came towards Rome, as far as the River Po. There he was met by Leo, whose fearless and eloquent intervention on behalf of the City, caused Attlia to turn aside and go back whither he had come. Later Genseric, King of the Vandals, invaded Rome, and Leo was able to induce him to be content with the pillage of the City, and to retire without further destruction thereof. * However, Leo was not only the defender of Rome against Attila and Genseric, who by their armies would have destroyed the City ; but of the whole Church against Nestorius and Eutyches, who by their heresies would have destroyed the Faith. Nestorius denied that the Child born of Mary was God. Against which heresy, the true Faith asserteth that the Person of God the Son, in his divine nature, took human nature from Mary, so that she was thus truly the Mother of God. Eutyches, in his zeal for Christ’s Godhead, denied that he hath two natures, to wit, the divine and human. And in 447 his followers assembled at Ephesus in the Robber Council ( as it was later called) and upheld his false teaching. At the same time they suppressed a long, dogmatic letter which Leo had written in definition of the true Faith. In 449 the General Council of Chalcedon was assembled, wherein was read the Dogmatic Letter of Leo. At this Council of Ephesus this Tome of Leo was adopted as the final definition of the Church regarding the two natures of her Lord. * In those days the office of preaching was allowed only to bishops. So he set about to instruct the church in Rome, which he purposed to make a pattern for all other churches. By sermons given at home, and letters sent abroad, many of which have been preserved, he took oversight of all God’s flock willingly. He restrained the heretical Manichaeans who had fled from the Vandals in Africa and settled in Rome. He refuted by letters sent to Spain the heresy of Priscillianism, which was making headway there. As Patriarch of the West, he acted promptly and firmly to secure justice and good order throughout the Western Church. He decreed that only men of mature years and disciplined mind and life should be ordained to the priesthood. He added to the Canon of the Mass the words : These holy and unspotted sacrifices : thus describing the oblations of bread and wine, for the Manichaeans taught that all natural things are evil. After many noteworthy acts, and after having written many things that are both holy and clear to the understanding, he fell asleep in God, in the twenty-second year of his pontificate, to wit, in 461, on November 10th. But his feast is kept on the day of the translation of his relicks, which are now enshrined in the Vatican Basilica.
Collect:O God, who by the words and acts of thy holy Doctor and Bishop Saint Leo, didst withstand the enemies of thy sacred humanity and of thy Church : grant we beseech thee, that we, being guided by the light of his teaching, may be enabled to walk in his path of virtue, through Jesus Christ thy Son our Lord, who livest and reignest, with thee and the Holy Ghost, one God for ever and ever. Amen.