Columbia subject headings:
Harvard subject headings:
Church and state--Germany--History
Church history--Middle Ages, 600-1500
Germany--Church history--843-1517.
Germany--History--Henry IV, 1056-1106.
Investiture.
Princeton subject headings:
Church and state--Germany--History.
Church history--Middle Ages, 600-1500.
Germany--Church history--843-1517.
Germany--History--Henry IV, 1056-1106.
Investiture.