Columbia subject headings:
Emperors--Biography.
France--Kings and rulers--Biography.
Louis I, Emperor, 778-840.
Harvard subject headings:
France--History--To 987.
France--Kings and rulers--Biography.
Louis I, Emperor, 778-840.
Princeton subject headings:
France--History--To 987.
France--Kings and rulers--Biography.
Louis I, Emperor, 778-840.