Columbia subject headings:
France--History--Charles II, 840-877.
France--Kings and rulers--Religious aspects.
Holy Roman Empire--History.
Holy Roman Empire--Kings and rulers--Religious aspects.
Harvard subject headings:
France--History--Charles II, 840-877.
France--Kings and rulers--Religious aspects.
Holy Roman Empire--History--843-1273.
Holy Roman Empire--History.
Holy Roman Empire--Kings and rulers--Religious aspects.
Learning and scholarship--History--Medieval, 500-1500
Princeton subject headings:
Charles II, King of France, 823-877.
France--Civilization--700-1000.
France--Court and courtiers.
France--History--Charles II, 840-877.