OPENING OF THE HOLY DOOR
It was established by Pope Celestine V in 1294 with the issuance of the Bull of Pardon. On August 29 of that year, in the Basilica of Santa Maria di Collemaggio, he was given the pontifical vestments and became pope with the name Celestine V.
On September 29, 1294, he promulgated the Bull of Pardon, granting a plenary indulgence to all humanity. To obtain forgiveness, he set only two conditions: entry into the Basilica of Santa Maria di Collemaggio—between the evening of August 28th and the evening of August 29th (the anniversary of his investiture) each year—and being "truly repentant and confessed."
On September 14, 1994, the Holy See, by mandate of Saint John Paul II, also granted a perpetual Plenary Indulgence to the Monastery of San Ruggero in Barletta for August 29th.