Columbia subject headings:
Church and state--Europe--History.
Europe--Church history--600-1500.
Investiture.
Monasticism and religious orders--Europe--History.
Harvard subject headings:
Church and state--Europe--History
Europe--Church history--600-1500.
Investiture.
Monasticism and religious orders--Europe--History--Middle Ages, 600-1500.
Monasticism and religious orders--Europe--History.
Princeton subject headings:
Church and state--Europe--History.
Europe--Church history--600-1500.
Investiture.
Monasticism and religious orders--Europe--History.