St Leo was only one of the two popes who has the title "Great" His innate greatness was his pronounced humility in all things. Although he was truly a scholar of immense ability, Leo's life was truly "hid with Christ in God." (Col 3:3)
Pope Leo the Great was known for his diplomatic negotiation with Atilla the Hun. By his charm and wisdom, gifts of God, he was able to persuade Atilla, the barbarian not to burn the city in 455.
pic credit: wikipedia
Place: Vatican City
"Throughout St Leo's preaching, he shows a single fascination for 'the mysteries of Christ.' The mysteries are eternal: Veiled in the Old Testament, signified in the New, they will be fully revealed in glory, in eternity."
St Leo, an exemplary pope and saint and a true disciple of Christ! His work will stand throughout history but his virtue of humility and obedience to God will
Source: Hahn, Scott and Aquilina, Mark. Living the Mysteries: A Guide for Unfinished
Christians. Huntington, Indiana: Our Sunday Visitor. 2003.