Columbia subject headings:
Harvard subject headings:
Europe--History--476-1492--Congresses.
Europe--History--Congresses.
Europe--History--To 476--Congresses.
History, Ancient--Congresses
Imperialism--History--To 1500--Congresses.
Middle Ages--Congresses
Rome--History--Congresses.
Princeton subject headings:
Europe--History--476-1492--Congresses.
Europe--History--To 476--Congresses.
History, Ancient--Congresses.
Middle Ages--Congresses.