Pope Leo I
c. 400 – 461 · Bishop of Rome
Also known as Leo the Great · Leo Magnus
Feast: 10 November (Catholic) · 18 February (Orthodox)

Bishop of Rome 440-461. His Tome (Epistula 28) was acclaimed at the Council of Chalcedon (451). Negotiated with Attila in 452.
Highlights
- Main contribution
- Leo gave the Council of Chalcedon a letter it could build on.
- Event connection
- Council of Chalcedon (451)
- Best first read
- Tome (Letter to Flavian)
- Primary source
- Leo, Tomus ad Flavianum (Ep. 28)
Leo gave the Council of Chalcedon a letter it could build on. His Tome to Flavian explained Christ as one person in two natures, without confusion and without division, and the council received it as a decisive statement of orthodox Christology. Leo also strengthened the role of the Bishop of Rome as a teacher and negotiator in a West under pressure. The meeting with Attila in 452 became the famous image, but the Tome is the deeper reason his influence lasted.
Notable works
- ·Tome (Letter to Flavian) · 449
- ·Sermons · 450
Primary sources
- ·Leo, Tomus ad Flavianum (Ep. 28)
- ·Leo, Sermones
- ·Acta Concilii Chalcedonensis (451)

Book of the day
Tome (Letter to Flavian)
Pope Leo IA reading pick tied to today's figure, quote, era, or event. Leo's letter becomes a central text for Chalcedon and the two-natures formula.
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