The Feast of the Most Holy Body and Blood of Christ, historically known by its Latin name, Corpus Christi, celebrates the Real Presence of Jesus Christ in the Holy Eucharist—Body, Blood, Soul, and Divinity. It is traditionally celebrated on the Thursday following Trinity Sunday.
St. Juliana of Mont Cornillon
The Feast of Corpus Christi originated in 1246 when Robert de Torote, bishop of Liege, ordered a special feast in honor of the Blessed Sacrament in his diocese. He was persuaded to initiate the feast by St. Juliana, prioress of Mont Cornillon in Belgium (1193-1258). St. Juliana had a series of visions in which she was instructed by Our Lord to work to establish a liturgical feast for the Holy Eucharist, to which she had a great devotion.
After many years of trying, she finally convinced the bishop who was, at that time, assisted by Jacques Pantaleon, archdeacon of Liege and future Urban IV.
Eucharistic Miracle of Bolsena
In 1263 a German priest, Peter of Prague, stopped at Bolsena, Italy while on a pilgrimage to Rome. He is described as being a pious priest, but one who found it difficult to believe that Christ was actually present in the consecrated Host. While celebrating Holy Mass above the tomb of St. Christina (located in the church named for this martyr), he had barely spoken the words of Consecration when blood started to seep from the consecrated Host and trickle over his hands onto the altar and the corporal.
The priest was immediately confused. At first, he attempted to hide the blood, but then he interrupted the Mass and asked to be taken to the neighboring city of Orvieto, the city where Pope Urban IV was then residing.
The pope listened to the priest's account and absolved him. He then sent emissaries for an immediate investigation. When all the facts were ascertained, he ordered the bishop of the diocese to bring to Orvieto the Host and the linen cloth bearing the stains of blood. With archbishops, cardinals, and other ecclesiastical dignitaries in attendance, the Pope met the procession and, amid great pomp, had the relics placed in the cathedral. The linen corporal bearing the spots of blood is still reverently enshrined and exhibited in the cathedral of Orvieto.
Two Saints in A Contest
Pope Urban IV was prompted by this miracle to institute a new feast for the whole Church. He wanted a Mass and office written especially for this new important feast of the Holy Eucharist. It was this difficult and essential task that was appointed to both Sts. Bonaventure and Thomas Aquinas. The holy father reserved to himself the right of choosing which of these two great men’s writings would be used.
So on the appointed day, both Saints, each with his manuscript under his arm, came before the Vicar of Christ. St. Thomas was to go first, and kneeling before the pope, began to read what he had written. Both Pope Urban IV and St. Bonaventure listened with tears of emotion to the beautiful work of this Saint. And while St. Thomas was still reading, St. Bonaventure turned aside and tore his manuscript into small pieces. When St. Bonaventure's turn came, he admitted what he had done and told them that he was no longer in possession of his manuscript. St. Bonaventure explained that he considered St. Thomas’ work alone worthy to be used at the Most Holy Feast, therefore making it unnecessary to take his own poor work into account.
And for centuries now on the feast of Corpus Christi, within every Catholic church is heard that heavenly hymns written by the hand of St. Thomas Aquinas: the Pange lingua, Tantum ergo, and Panis angelicus.
Papal Bull Transiturus
One year after the miracle of Bolsena, in August of 1264, Pope Urban IV introduced the saint's composition, and by means of the papal bull Transiturus, he instituted the feast of Corpus Christi.
We should celebrate continuously the memory of this memorial, because the more frequently his gift and favor are looked upon, so much the more firmly are they kept in memory. Therefore, although this memorial Sacrament is frequented in the daily solemnities of the Mass, we nevertheless think suitable and worthy that, at least once a year – especially to confound the lack of faith and the infamy of heretics – a more solemn and honorable memory of this Sacrament be held. This is so because on Holy Thursday, the day on which the Lord himself instituted this Sacrament, the universal Church, occupied with the reconciliation of penitents, blessing the chrism, fulfilling the Commandments about the washing of the feet and many other such things, is not sufficiently free to celebrate so great a Sacrament.
Moreover, we know that, while we were constituted in a lesser office, it was divinely revealed to certain Catholics that a feast of this kind should be celebrated generally throughout the Church. Therefore, to strengthen and exalt the Catholic Faith, we decree that, besides the daily memory that the Church makes of this Sacrament, there be celebrated a more solemn and special annual memorial. Then let the hearts and mouths of all break forth in hymns of saving joy; then let faith sing, hope dance, charity exult, devotion applauds, the choir be jubilant, and purity delight. Then let each one with a willing spirit and prompt will come together, laudably fulfilling his duties, celebrating the Solemnity of so great a Feast.