Columbia subject headings:
Papacy--History.
Popes--Temporal power--History.
Harvard subject headings:
Church and state--Europe--History
Church history--Middle Ages, 600-1500
Papacy--History
Popes--Temporal power--History.
Princeton subject headings:
Church and state--Europe--History.
Church history--Middle Ages, 600-1500.
Papacy--History.
Popes--Temporal power--History.