You were the Church's instrument
in strengthening the teaching of true doctrine;
you shone forth from the West like a sun dispelling the errors of the heretics.
Righteous Leo, entreat Christ God to grant us His great mercy.
During his pontificate the Council of Chalcedon was convened. It condemned many popular heresies of the day, and declared that the two natures of Jesus were indivisible. Pope Leo had already defended this doctrine in the epistle called the Tome. When the Council Fathers read it they declared, “This we all believe. Peter has spoken through Leo.”
St. Leo the Great was Pope during the middle of the fifth century, a troubled time when barbarian armies were ravaging the once mighty Roman Empire. For all intents and purposes, the Western Empire was in total political and military collapse and there was a vacuum of political leadership. Pope St. Leo filled the void and became the advocate for the temporal as well as spiritual needs of his flock. He is perhaps most famous for persuading Attila the Hun to abandon his plans to sack the city of Rome and to withdraw his forces beyond the Danube river (452). St. Leo once again was the spokesperson for the Roman citizenry in 455 when the Vandal barbarians swept into Central Italy, securing concessions from them.
Through both his powerful teaching and his leadership, Pope St. Leo the Great very much strengthened the office of the Papacy and made a strong biblical case for the Divine institution of this ministry by examining the biblical evidence for Peter’s unique role among the apostles.”
- courtesy of Dr. Marcellino D’Ambrossio