Columbia subject headings:
Alliances--Congresses.
Europe--Foreign relations--Congresses.
Europe--Politics and government--476-1492--Congresses.
Political science--Europe--History--Congresses.
Harvard subject headings:
Alliances--Congresses.
Europe--Foreign relations--Congresses.
Europe--Politics and government--476-1492--Congresses.
Political science--Europe--History--Congresses.
Princeton subject headings:
Europe--Foreign relations.
Europe--Politics and government--476-1492.
Middle Ages.