Columbia subject headings:
Harvard subject headings:
Germany--History--Henry IV, 1056-1106.
Henry IV, Holy Roman Emperor, 1050-1106.
Holy Roman Empire--History--Henry IV, 1056-1106.
Investiture--History.
Social conflict--Holy Roman Empire--History.
Princeton subject headings:
Germany--History--Henry IV, 1056-1106.
Henry IV, Holy Roman Emperor, 1050-1106.
Holy Roman Empire--History--Henry IV, 1056-1106.
Social conflict--Holy Roman Empire--History.