Possible Clues:

• Fifth-cen. pope
• 'Great' pope of the fifth century
• Canonized pope who persuaded Attila not to attack Rome
• Fifth-cen. pope called "The Great"
• Pope known as "The Great"
• Florida univ. named for a canonized pope
• Canonized 5th-century pope
• Canonized pope known as "The Great"
• Canonized pope known as 'The Great'
• Fifth-cent. canonized pope