Columbia subject headings:
Byzantine Empire--Foreign relations--Holy Roman Empire.
Charlemagne, Emperor, 742-814--Coronation.
Holy Roman Empire--Foreign relations--Byzantine Empire.
Harvard subject headings:
Byzantine Empire--Foreign relations--Holy Roman Empire.
Charlemagne, Emperor, 742-814--Coronation.
Holy Roman Empire--Foreign relations--Byzantine Empire.
Princeton subject headings:
Byzantine Empire--Foreign relations--France.
Charlemagne, Emperor, 742-814.
France--Foreign relations--Byzantine Empire.
France--History--To 987.