Possible Clues:

• Papal name last taken in 1939
• Common papal name
• Name used by a dozen popes
• With more of a score, Pole becomes Pope
• Name chosen 12 times by 33 Down
• __ XII, WWII pope
• Apt name chosen by 12 Popes
• Devout pronouncement for religious leader
• Apt papal name
• Pope from Italy's more Saint