Refers to a Christian feast and festival commemorating the origin of the eucharist and in honor of the presence of the body of Jesus Christ in the eucharist. The Latin term means 'body of Christ.' It is usually celebrated on the Thursday after Trinity Sunday in the Western church. Its origins lie in the Middle Ages when there was increased devotion to the Blessed Sacrament, especially after the Fourth Lateran Council of 1215. In 1246, Robert de Torote, bishop of Liège, first celebrated the feast in his diocese after being persuaded to do so by Blessed Juliana, prioress of Mont Cornillon near Liège (1222-58), who had experienced a vision. The feast did not spread until Jacques Pantaléon, formerly archdeacon of Liège, became Pope Urban IV; a bull of 1264 commanded its observance. Over time it became more accepted and in the 15th century it became, in effect, the main feast of the church. Corpus Christi has been celebrated by carrying the host in procession since the 14th century. The feast's procession became a pageant in which sovereigns, princes, magistrates, and guild members took part. In the 15th century the procession was often followed by performances of miracle plays and mystery plays by members of guilds. The feast was suppressed in Protestant churches after the doctrine of transubstantiation was rejected during the Reformation.