Columbia subject headings:
Harvard subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Europe--Church history--600-1500--Congresses.
Persecution--History--Middle Ages, 600-1500--Congresses.
Proselytizing--Europe--History--Congresses.
Violence--Religious aspects--Christianity--Congresses.
Princeton subject headings:
Evangelistic work--Europe--History--To 1500--Congresses.