Columbia subject headings:
Germany--History--Hohenstaufen, 1138-1254.
Henry, Duke of Saxony, 1129-1195.
Harvard subject headings:
Germany--History--Hohenstaufen, 1138-1254.
Henry, Duke of Saxony, 1129-1195.
Princeton subject headings:
Germany--History--Hohenstaufen, 1138-1254.
Henry, Duke of Saxony, 1129-1195.