The feast of St. Anthony of Padua
The translation of his relics, that is.
I’m fairly certain this day is no longer celebrated outside of Padua as a memorial of St. Anthony of Padua. (Perhaps not even there.) February 15 was observed in the old Franciscan calendar as the feast of the Translation of the relics of St. Anthony. St. Bonaventure was present at the event, but I am unsure as to what year the translation actually took place.
Feast days in honor of the translation of relics (remains of the saints) date back to the at least the 2nd century. Liturgical celebrations, along with processions, and days of prayer honoring the saint reached a zenith in the Middle Ages. Since then, until the Second Vatican Council, these celebrations continued to be conducted with equal solemnity and pomp. I am not certain how things are done today. We should have an opportunity to witness one such event with the upcoming translation of the relics of St. Padre Pio into his new shrine at San Giovanni Rotondo.
On the translation of relics:
At the same time the solemnity attached to translations was by no means a peculiarity of the Celts. The story of the translation of St. Cuthbert’s remains is almost as marvellous as any in Celtic hagiography. The forms observed of all-night vigils, and the carrying of the precious remains in “feretories” of gold or silver, overshadowed with silken canopies and surrounded with lights and incense, extended to every part of Christendom during the Middle Ages. Indeed this kind of solemn translation (elevatio corporis) was treated as the outward recognition of heroic sanctity, the equivalent of canonization, in the period before the Holy See reserved to itself the passing of a final judgment upon the merits of deceased servants of God, and on the other hand in the earlier forms of canonization Bulls it was customary to add a clause directing that the remains of those whose sanctity was thus proclaimed by the head of the Church should be “elevated”, or translated, to some shrine above ground where fitting honour could be paid them. - New Advent
On the commemoration of a feast for relics:
It has long been customary especially in churches which possessed large collections of relics, to keep one general feast in commemoration of all the saints whose memorials are there preserved. An Office and Mass for this purpose will be found in the Roman Missal and Breviary, and though they occur only in the supplement Pro aliquibus locis and are not obligatory upon the Church at large, still this celebration is now kept almost universally. The office is generally assigned to the fourth Sunday in October. In England before the Reformation, as we may learn from a rubric in the Sarum Breviary, the Festum Reliquiarum was celebrated on the Sunday after the feast of the Translation of St. Thomas of Canterbury (7 July), and it was to be kept as a greater double “wherever relics are preserved or where the bodies of dead persons are buried, for although Holy Church and her ministers observe no solemnities in their honour, the glory they enjoy with God is known to Him alone.” - New Advent
PRAYER TO ST ANTHONY FOR THE RECOVERY OF LOST GRACES
O great and faithful friend of the Lord, who, by the great purity of thy heart, didst merit to see and converse with Him even in this life, thou to whom He has granted, according to the firm belief of the faithful, the gift of recovering for those who invoke thee the precious gifts which they had lost, obtain for us (or for N.) by thy prayers and merits, all the holy friendship and union with God which we should have had if we had always been faithful to Him. Amen. - Source
