About Pope St Leo the Great Image

Pope St Leo the Great (Pope Leo I) was a fifth century pope who combated the heresies of Pelagianism, Manichaeism, and Monophysitism. He also miraculously repelled Attila the Hun from invading Rome.

Read the full Pope St Leo the Great novena on the novena page. You can also learn more about novenas here.

What Did Pope St Leo the Great Do?

Pope Saint Leo the Great was born, probably in Tuscany, to a Roman aristocratic family.

Leo became respected while serving under Pope Celestine I in 431 AD.

He was known for his keen intellect and love for Christ. He would use his skills of persuasion to reconcile factions in the Church.

In 440, Leo was elected as pope to succeed Pope Sixtus III.

During this pontificate, he overcame the Pelagian heresy, which denied Original Sin and claimed that we could be good and make it to Heaven on our own steam, without God’s grace.

Pope Leo also fought against Manichaeism, a bizarre heresy that viewed creation and matter as evil.

Within the Church, a great debate arose of whether Christ had one divine nature or two natures: human and divine.

Pope Leo wrote a famous letter that settled the heresy: Jesus Christ is One Person but has both a human and a divine nature, which cannot be separated. This refuted the heresy of the Monophysites.

Pope Leo died on November 10th, 461.

Pope Benedict XIV declared in 1754 that Pope Leo I was a Doctor of the Church.