Per amorem Tui in tabernaculo pro me viventis, Miserere mei et salva me.
The Solemnity of Corpus Christi commemorates the Holy Eucharist, paralleling Holy Thursday commemorating Our Lord’s institution of the Eucharist. Corpus Christi was introduced in the late 13th century to encourage the faithful to give special honour to the Blessed Sacrament and it is still on the Roman Missal’s official Calendar for the universal Church on Thursday after Trinity Sunday (today).
Corpus Christi became a mandatory feast in the Roman Church in 1312. But nearly a century earlier, Saint Juliana of Mont Cornillon, promoted a feast to honour the Blessed Sacrament. From an early age Juliana, who became an Augustinian nun in Liége, France, in 1206, had a great veneration for the Blessed Sacrament, and longed for a special feast in its honour. She had a vision of the Church under the appearance of the full moon having one dark spot, which signified the absence of such a solemnity. She made known her ideas to the Bishop of Liége, Robert de Thorete, to the Dominican Hugh who later became cardinal legate in the Netherlands, and to Jacques Panaléon, at the time Archdeacon of Liége and who later became Pope Urban IV. Bishop Robert de Thorete ordered that the feast be celebrated in his diocese.
Pope Urban IV then published the Bull Transiturus (September 8, 1264), in which, after having extolled the love of Our Saviour as expressed in the Holy Eucharist, ordered the annual celebration of Corpus Christi on the Thursday after Trinity Sunday. More than four decades later, Pope Clement V published a new decree which embodied Urban IV’s decree and ordered the adoption of the feast at the General Council of Vienna (1311). Pope John XXII, successor of Clement V, urged this observance.
The processions on Corpus Christi to honour the Holy Eucharist soon became a principal feature of the feast’s celebration by the faithful, and became a tradition throughout Europe. These processions were endowed with indulgences by Popes Martin V and Eugene IV.