Originally published at The Catholic Thing
On the Saturday before the second Sunday of Lent in 445, Pope Leo, whose pontificate spanned more than twenty years, preached a powerful sermon on the Transfiguration. It is one of the nearly one hundred sermons that have been preserved from the first bishop of Rome to have been called Leo (twelve others would follow). The sermons hold the distinction of being the first papal homilies that have come down to us that were preached to the people during liturgical celebrations.
This was the same Leo who would earn the title “the Great” because of his many notable accomplishments. One such was his decisive intervention at the Fourth Ecumenical Council, the Council of Chalcedon of 451, which cemented the Christological doctrine of the three previous councils. This came by way of a letter (known as the Tome of Leo) that was read to the hundreds of assembled bishops, who, upon the completion of its reading, acclaimed in unison: “Peter has spoken through the mouth of Leo.”
Another memorable episode took place the very next year when Leo was instrumental in preventing the sacking of Rome by Attila the Hun. When the latter entered Italy in 452, he began to sack
