Columbia subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Papacy--History--To 1309--Congresses.
Harvard subject headings:
Church and state--Congresses
Papacy--History--Congresses.
Popes--Primacy--Congresses.
Popes--Temporal power--Congresses.
Princeton subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Papacy--History--To 1309--Congresses.