The Church celebrates today the feast of Pope Saint Leo I, known as St. Leo the Great, one of the most remarkable leaders of the early Church. His firm defense of Christian teaching and his courageous leadership during times of crisis earned him great respect throughout history.
Leo’s early life remains partly unknown, including the exact place and date of his birth. He is believed to have come from Tuscany or possibly Rome. Around the year 430, during the pontificate of Pope Celestine I, Leo became a deacon in Rome. His wisdom and leadership were soon recognized, and Emperor Valentinian III later sent him to Gaul to resolve a dispute between government and military officials.
While Leo was still on this mission, Pope Sixtus III passed away in 440. The people of Rome chose Leo as the next Bishop of Rome, a role he would hold for more than twenty years. As pope, he worked tirelessly to preserve unity in the Church, strengthen the faith, and protect his people from the dangers threatening the city.
Pope Leo confronted several false teachings that spread during his time. These included Pelagianism, which denied the existence of Original Sin, and Manichaeanism, which claimed that all matter was evil. He also played a major role in resolving disputes in the Eastern Church concerning the divine and human natures of Jesus Christ.
In 451, the Council of Chalcedon, one of the most important gatherings in Church history, accepted Leo’s teaching as the true explanation of Christ’s nature. His famous letter, known as the *Tome of Leo*, affirmed that Jesus Christ is both fully divine and fully human, united in one person without confusion or division. The bishops present at the council declared with joy, “Peter has spoken through the mouth of Leo.”
In his teachings, Leo explained that Christ’s divine glory was not lost when He became man. “The Lord of the universe veiled his measureless majesty and took on a servant’s form,” he wrote. “The God who knew no suffering did not refuse to become a suffering man.”
Leo’s courage in times of danger also became legendary. In 452, he met Attila the Hun and convinced him to turn back, saving Rome from destruction. A few years later, in 455, when the Vandals invaded, Leo once again stepped forward to negotiate peace and protect the people and the churches of the city.
Pope St. Leo the Great died on November 10, 461. In 1754, Pope Benedict XIV declared him a Doctor of the Church in recognition of his lasting contribution to Christian theology. Many of his sermons and writings still survive and continue to inspire readers today.
St. Leo is also honored in the Eastern Orthodox and Eastern Catholic Churches, where his feast is celebrated on February 18.
Reflecting on his life, Pope Benedict XVI said in 2008, “As the nickname soon attributed to him by tradition suggests, he was truly one of the greatest pontiffs to have honoured the Roman See.”
Even after fifteen centuries, St. Leo’s faith, wisdom, and courage remain a guiding light for the Church and for all who seek truth and peace.