Pope Leo I

Pope Saint Leo I
Bishop of Rome
Miniature which depicts Leo I, contained in the Menologion of Basil II (c. 1000 AD, Vatican Library)
Church	Catholic Church
Papacy began	29 September 440
Papacy ended	10 November 461
Predecessor	Sixtus III
Successor	Hilarius
Personal details
Born	Leo c. 400 AD Tuscany, Western Roman Empire
Died	(461-11-10)10 November 461 (aged 60 – 61) Rome, Western Roman Empire
Sainthood
Feast day	10 November 11 April (pre-1969 calendar) 18 February (Eastern Orthodoxy)
Venerated in	Catholic Church Eastern Orthodox Church Anglican Communion Church of the East
Attributes	Papal vestments Papal tiara Staff
Theological work
Era	Post-Nicene
Language	Latin
Tradition or movement	Chalcedonism
Main interests	Christology
Notable ideas	Chalcedonian Definition
Other popes named Leo

Pope Leo I (c. 400 – 10 November 461), also known as Leo the Great,^[1] was Bishop of Rome^[2] from 29 September 440 until his death. He is the first of the three Popes listed in the Annuario Pontificio with the title "the Great",^[3] alongside Popes Gregory I and Nicholas I.

Leo was a Roman aristocrat. He is perhaps best known for having met Attila the Hun in 452 and persuading him to turn back from his invasion of Italy. He is also a Doctor of the Church, most remembered theologically for issuing the Tome of Leo, a document which was a major foundation to the debates of the Council of Chalcedon, the fourth ecumenical council. That meeting dealt primarily with Christology and elucidated the definition of Christ's being as the hypostatic union of two natures, divine and human, united in one person, "with neither confusion nor division". It was followed by a major schism associated with Monophysitism, Miaphysitism and Dyophysitism.^[4] He also contributed significantly to developing ideas of papal authority.