Columbia subject headings:
Diplomacy--History--To 1500.
Europe--Kings and rulers--To 1500.
Monarchy--Europe--History--To 1500.
Harvard subject headings:
Diplomacy--History--To 1500.
Europe--Kings and rulers--Congresses--History--To 1500.
Europe--Kings and rulers--History--To 1500.
Monarchy--Europe--History--To 1500.
Privy councils--Europe--History--To 1500.
Princeton subject headings: