The Portiuncula (small portion) refers to the land in Assisi, Italy, that belonged to the Benedictines. On this land was an old church dedicated to the Virgin Mother of God but abandoned. When he saw that the church was deserted, St. Francis began to live there and repair it. He heard that the angels often visited it, so that it was called St. Mary of the Angels.
In 1216, in a vision, St Francis obtained from Jesus Himself the Indulgence of the Pardon of Assisi that was approved by Pope Honorius III. This indulgence has been extended to all parish churches throughout the world.
The date was set from vespers of the first of August until sundown on the second of August, the Feast of Our Lady of the Angels. It is said that St. Francis was given this day by Our Lord because the Feast of the Chains of St. Peter celebrated on August first is the day Peter was released from prison and his chains removed. This is an extraordinary demonstration of God’s mercy in removing the chains of sin from those who devoutly and faithfully seek to gain the indulgence by completing its requirements.
The Portiuncula indulgence is the first plenary indulgence that was ever granted in the Church. To gain it, one must worthily receive the Sacraments of Penance (eight days before or after, and have no attachment to venial sin) and of the Blessed Eucharist (attend Holy Mass) and to say in a church of the Franciscans or in the parish church the customary prayers for an indulgence (according to "The Raccolta", 1957, the prayers for the intentions of the Supreme Pontiff for the Portiuncula Indulgence consist of "at least SIX TIMES Our Father, Hail Mary and Glory be, at each visit") .
What distinguishes the Portiuncula, indulgence especially from all others is, that on the day on which it is granted, it can be gained not only once, but oftener, as often as on that day you visit a church of the Franciscans, or the parish church, and there pray for some time according to the intention of the Holy Father. The Portiuncula indulgence can be gained more that once on the same day, for we may apply it to the souls in purgatory, if we gain it the second and the third time, etc.
Note: The norms and grants of indulgences were reformed by Pope Paul VI after the Second Vatican Council in his Apostolic Constitution "Indulgentiarum Doctrina" (1967), and the Portiuncula Indulgence was again confirmed at that time. According to the Enchiridion Indulgentiarum, the Catholic faithful may gain a plenary indulgence on 2 August (the Portiuncula) or on such other day as designated by the local ordinary for the advantage of the faithful, under the usual conditions (sacramental Confession, Holy Communion, and prayer for the intentions of the Supreme Pontiff), by devoutly visiting the parish church, and there reciting at least the Lord's Prayer and the Creed. The Indulgence applies to the cathedral church of the diocese, and to the co-cathedral church (if there is one), even if they are not parochial, and also to quasi-parochial churches. To gain this, as any plenary indulgence, the faithful must be free from any attachment to sin, even venial sin. Where this entire detachment is wanting, the indulgence is partial.