Editing Pope Leo I (section)

== Early life ==
According to the ''[[Liber Pontificalis]]'', he was a native of [[Tuscany]] and son of Quintianus or Quintilianus. By 431, as a [[deacon]], he was sufficiently well known outside of Rome that [[John Cassian]] dedicated to him the treatise against [[Nestorius]] written at Leo's suggestion. About this time [[Cyril of Alexandria]] appealed to Rome regarding a jurisdictional dispute with [[Juvenal of Jerusalem]], but it is not entirely clear whether the letter was intended for Leo in his capacity as [[archdeacon]],<ref name=Butler>{{Cite web|url=https://www.bartleby.com/lit-hub/lives-of-the-saints/volume-iv-april/st-leo-the-great-pope/|title=St. Leo the Great, Pope|date=January 12, 2023|website=Collection at Bartleby.com}}</ref> or for [[Pope Celestine I]] directly.

Near the end of the reign of [[Pope Sixtus III]], Leo was dispatched at the request of [[Valentinian III|Emperor Valentinian III]] to settle a dispute between [[Flavius Aetius|Aëtius]], one of the chief Roman military commanders in Gaul, and the chief magistrate [[Albinus (consul 444)|Albinus]]. [[Johann Peter Kirsch]] sees this commission as a proof of the confidence placed in the able deacon by the Imperial Court.<ref name="Kirsch1910" />