Feast of Corpus Christi, also called Solemnity of the Most Holy Body and Blood of Christ, festival of the Roman Catholic Church in honour of the real presence of the body (corpus) of Jesus Christ in the Eucharist. A movable observance, it is observed on the Thursday (or, in some countries, the Sunday) after Trinity Sunday and is a holy day of obligation in many countries. The Feast of Corpus Christi originated in 1246 when Robert de Torote, bishop of Liège, ordered the festival celebrated in his diocese. He was persuaded to initiate the feast by St. Juliana, prioress of