Columbia subject headings:
Church history--Middle Ages, 600-1500.
Monasticism and religious orders--History--Middle Ages, 600-1500.
Papacy--History.
Political science--History.
Harvard subject headings:
Church history--Middle Ages, 600-1500
Monasteries--Europe--History.
Papacy--History
Political science--Europe--History
Princeton subject headings:
Church and state--Catholic Church--History.
Church and state--Europe--History.
Church history--Middle Ages, 600-1500.
Monasticism and religious orders--History--Middle Ages, 600-1500.
Papacy--History.
Political science--History.