Columbia subject headings:
Harvard subject headings:
Church and state--Catholic Church--History
Church and state--Europe--History
Church history--Middle Ages, 600-1500
Middle Ages
Middle Ages--Historiography
Zerbi, Piero.
Princeton subject headings:
Church and state--Catholic Church--History.
Church and state--Europe--History.
Church history--Middle Ages, 600-1500.
Middle Ages--Historiography.
Middle Ages.
Zerbi, Piero.