Columbia subject headings:
Harvard subject headings:
Frederick II, Holy Roman Emperor, 1194-1250--Fiction.
Frederick II, Holy Roman Emperor, 1194-1250.
Germany--History--Frederick II, 1215-1250.
Holy Roman Empire--History--Frederick II, 1215-1250.
Italy--History--Germanic rule, 962-1268.
Princeton subject headings:
Fiction.
Frederick II, Holy Roman Emperor, 1194-1250--Fiction.
Novels.