The feast of Corpus Christi is a 'Solemnity' in the Latin calendar. Traditionally celebrated on the Thursday after Trinity Sunday.
The feast traces back to the 12th century, beginning with St Juliana de Cornillon (b 1191/2) who was placed, an orphan, at five years of age in the convent of Cornillon, also known as St Juliana of Liège (the diocese).
The Sacrament of the Eucharist is at the heart of every Mass, and 'Eucharistic worship' or 'Eucharistic adoration' was not unknown in the church, and was central in the lives of many saints and mystics, as it was in the life of St Juliana. At 16 she began experiencing visions during these periods of prayer. She saw the full moon, crossed by a dark stripe. In her own understanding the moon signified the life of the Church, and the opaque line signified the absence of a particular liturgical feast day dedicated to the celebration of the Eucharist.
Juliana kept her revelations a secret for about 20 years. She then confided it to two women who would join her in the practice, one a hermit, the other a sister at the convent, of which Juliana was now Prioress. They told John of Lausanne, a canon of the Church of St Martin in Liège, who sought advice and promoted the practice.
Robert Torote, Bishop of Liège, accepted their proposal and introduced the Solemnity of Corpus Christi in his diocese. Other Bishops following his example instituted this Feast in their diocese.
Typically, she encountered harsh opposition from some of the clergy, including the superior on whom her convent depended, Juliana was obliged to leave the convent, with several companions, and for the next 10 years until her death (1258) they were guests at various Cistercian convents.
One Jacques Pantaléon of Troyes was won over to the Feast during his ministry as Archdeacon in Lièges. He went on to become Pope Urban IV in 1264, and instituted the Solemnity of Corpus Christi on the Thursday after Pentecost as a Feast of the universal Church. Notably, on his staff at the time was a Dominican friar, Thomas d'Aquino – St Thomas Aquinas.
Celebration was limited, until John XXII, who 1317 re-established it in 1337.
The Feast was suppressed in the Reformation by the Protestant denominations who rejected the doctrine of 'the Real Presence' in the Eucharist. The Lutheran Church did not, and it continues in Lutheranism.
The Anglican Church also continued to celebrate the Feast and the doctrine. It was abolished in 1548 under the English Reformation, but was later reintroduced. Some Anglican churches now observe Corpus Christi, sometimes under the name "Thanksgiving for Holy Communion".
