Although theologians made a contribution to the process of defining doctrineDoctrine Belief (or system of beliefs) accepted as authoritative., ultimate responsibility lay with the bishops and from the fourth century final decisions were made at a succession of councils. The seven councils of bishops from East and West recognised by the Catholic church, were Nicea I (325), Constantinople I (381), Ephesus (431), Chalcedon (451), Constantinople II (553), Constantinople III (680-1) and Nicea II (787). After the schism between the churches of East and West the folowing Councils were recognised as ecumenical by the Western Church alone: Constantinople IV (869-70); Lateran I (1123); Lateran II (1139); Lateran III (1179); Lateran IV (1215); Lyons I (1245); Lyons II (1274); Vienne (1311-12); Constance (1414-18); Florence (1438-9); Lateran V (1512-17). The Fourth Lateran Council defined the doctrine of transubstantiation and required all adults to go to confessionConfession 1. Profession of faith. 2. Acknowledgement of one's sins. In the medieval church, sins were confessed to a priest as part of the Sacrament of Penance. and receive Communion every Easter