Prior to the revision of the Dominican liturgical calendar in 1961, the Thursday after Sexagesima Sunday was the feast of the Translation of the Relics of St. Catherine of Siena. In the 1909 Breviarium S.O.P., which contains the entire office, the feast had a rank of Totum Duplex. The office was essentially the same as the saint's feast on April 30th. The main difference is in the lessons and responsories at Matins.
It was announced in the Martyrology as follows:
THURSDAY AFTER SEXAGESIMA SUNDAY: Transferal of the body of St. Catherine of Siena, virgin, of the Order of Preachers.
From “Short Lives of the Dominican Saints” (London, Kegan Paul, Trench, and Trübner & Co., Ltd., 1901):
This festival was originally established under the name of the Commemoration of Saint Catherine of Siena or Feast of her Espousals, to perpetuate the memory of the mysterious favor conferred upon her in the year 1367, when the Saint had attained the age of twenty.
The city of Siena was given up to the riotous festivities usual at the close of the Carnival, and Catharine had shut herself up in her cell, seeking by prayer and fasting to make reparation for the offences committed by the thoughtless crowds who passed her door. Then our Lord appeared to her, and addressed her in these words : "Because thou hast forsaken all the vanities of the world and set thy love upon Me, and because thou hast, for My sake, rather chosen to afflict thy body with fasting than to eat flesh with others, especially at this time, when all others that dwell around thee, yea, and those also who dwell in the same house with thee, are banqueting and making good cheer, therefore I am determined this day to keep a solemn feast with thee and with great joy and pomp to espouse thy soul to Me in faith." As He was yet speaking, there appeared in the same place the most glorious Virgin Mary, Mother of God, the beloved disciple Saint John the Evangelist, Saint Paul the Apostle, and the great patriarch and founder of her Order, Saint Dominic; and after these came the kingly prophet and poet, David, with a musical psaltery in his hand, on which he played a heavenly melody of ineffable sweetness. Then our Blessed Lady came to Catharine and took her hand, which she held towards her Divine Son, and besought Him that He would vouchsafe to espouse her to Himself in faith. To which He consented with a very sweet and lovely countenance, and, taking out a ring that was set about with four precious pearls and had in the other part a marvelous rich diamond, He put the same on the finger of her right hand, saying thus, "Behold, I here espouse thee to Me, Thy Maker and Savior, in faith, which shall continue in thee from this time forward, evermore unchanged, until the time shall come of a blissful consummation in the joys of heaven. Now then, act courageously. Thou art armed with faith, and shalt triumph over all thy enemies." The vision disappeared, but the ring, invisible indeed to other eyes than Catharine's, remained upon her finger, a mysterious token of the love of her Divine Spouse.
We are expressly told that this event took place on "the last day of the Carnival," which in Siena was the Tuesday after Sexagesima; but, following the more general custom, the feast which commemorates it has always been kept on the Thursday. This feast was raised to a higher rank and its name changed to that of the Translation of the Relics of Saint Catherine in the year 1866.
The holy Virgin of Siena died in Rome, A.D. 1380, and was first interred in the cemetery adjoining the Church of Santa Maria sopra Minerva, but later on the sacred remains were removed by the Master of the Order, Blessed Raymond of Capua, formerly her confessor, to a stone sarcophagus on the right-hand side of the high altar of the church. When he had done this, he remembered what Saint Catharine had predicted to him on the Eve of Saint Francis, when they were together at Voragine on their journey back from Avignon, namely, that he should on that same day in a future year cause such a translation of her body to be made. Blessed Raymond afterwards detached the head from the body and sent it to the Convent of San Domenico at Siena, where it was at first carefully concealed, as the holy relic could not be exposed to public veneration before the Saint had been raised to the altars of the Church. Subsequently, however probably in the year 1385 Father Raymond made known to the Consistory of the Republic in what manner the head of their beloved fellow-citizen had been brought into their midst, and it was resolved that a grand festival should be celebrated and a solemn procession made to receive the sacred relic, as though it had been but newly brought to the city. The most touching feature in this celebration, of which minute accounts have been preserved to us, was the presence of the Saint's aged mother, Lapa, who walked in the ranks of the Sisters of the Third Order, close behind the canopy, beneath which was borne the head of her beloved child.
It would be tedious to speak of the various relics which at different periods have been detached from the holy body and bestowed on various convents of the Order; of the translation of the sacred remains to the Rosary Chapel, made by Saint Antoninus when Prior of the Minerva; and of yet a third translation, at the time of Saint Catharine's canonization. A fourth and last translation took place in our own times. On 17th April, A.D. 1855, when the Church of the Minerva was undergoing restoration, the Saint's sarcophagus was again opened by Father Alexander Vincent Jandel, General of the Order, on which occasion a considerable portion of the sacred relics was taken out and sent by his Most Revd. Paternity to Saint Dominic's Convent, Stone, the Mother-House of the English Congregation of Sisters of Penance, which bears the name of Saint Catharine. On August 4th of the same year, the restoration of the Minerva having been completed, Pius IX. of holy and happy memory consecrated the high altar with his own hands; and the remains of the Virgin Saint of Siena, after having been carried in solemn procession through the streets of the Eternal City, were, a few days later, laid to rest beneath the same high altar, where they still repose.
O God, you enabled the blessed Catherine, graced with a special privilege of virginity and patience, to overcome the attacks of evil spirits and to remain unshaken in your love; grant, we beseech you, that following her example by treading underfoot the wickedness of the world, and overcoming the wiles of our enemies, we may pass in safety to your glory. Through our Lord...