Columbia subject headings:
Charlemagne, Emperor, 742-814.
France--History--To 987--Sources.
Germany--History--To 843--Sources.
Holy Roman Empire--History--To 1517--Sources.
Harvard subject headings:
Charlemagne, Emperor, 742-814.
Princeton subject headings:
Charlemagne, Emperor, 742-814.
France--History--To 987--Sources.