Leo the Great

(d. Nov. 10, 461). Defender of orthodox Christology and pope. On Sept. 29, 440, he was consecrated Bishop of Rome. He was a great opponent of heresy, and his major accomplishment was his condemnation of Eutyches and Monophysitism and his defense of the permanent distinction of Christ's two natures in his one person. Leo's letter, called a Tome, was read at the Fourth Ecumenical Council at Chalcedon in 451. It stated clearly that Jesus Christ was one person in two natures. This was a great victory for Rome, for Leo, and for western theology. At Chalcedon the papal legate said, “Peter has spoken through the mouth of Leo.” The Definition of the Union of the Divine and Human Natures in the Person of Christ, adopted at Chalcedon, evolved from Leo's Tome. It is among the historical documents in the BCP (p. 864). Leo extended papal authority and advanced papal doctrine. He was declared a Doctor of the Church by Pope Benedict XIV. Leo is one of only two popes who are called “the Great.” He died in Rome. Leo is commemorated in the Episcopal calendar of the church year on Nov. 10.