Innocent III called this council to legislate rather than to define, and its seventy canons reached further into ordinary life than those of any council before it. Canon twenty-one required every Christian who had reached the age of discretion to confess their sins to their own priest at least once a year and to receive communion at Easter, which built the confessional into the annual rhythm of the medieval parish and generated a whole literature of manuals for confessors.
The first canon states the faith and uses the word transubstantiated of the eucharistic elements, the earliest use of the term in a conciliar text, though the theology it names was already current in the schools. Other canons regulated clerical conduct, forbade the founding of new religious orders without approval, restricted the multiplication of relics and required that new relics be authenticated, and ordered the clergy to stop taking part in trials by ordeal, a prohibition that effectively ended judicial ordeal in Latin Europe within a generation.
More than twelve hundred prelates attended, with representatives of secular rulers, and the council also authorised a crusade and settled several political disputes. It is the high point of the medieval papal monarchy in the sense that it is the moment when a single assembly under a single pope legislated for the religious practice of Western Europe and was largely obeyed.