Columbia subject headings:
Church and state--Europe--History--To 1500--Congresses.
Church history--Middle Ages, 600-1500--Congresses.
Harvard subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Church history--Modern period, 1500---Congresses.
Princeton subject headings:
Church and state--Europe--History--To 1500--Congresses.
Church history--Middle Ages, 600-1500--Congresses.