Columbia subject headings:
Germany--History--843-1273.
Guelf, House of--History.
Holy Roman Empire--History--843-1273.
Harvard subject headings:
Germany--History--843-1273.
Guelf, House of--History.
Holy Roman Empire--History--843-1273.
Princeton subject headings:
Germany--History--843-1273.
Guelf, House of--History.
Holy Roman Empire--History--843-1273.