The Rule of St. Francis obliges that all clerics perform their duties according the “Ordo of the Roman Church”, which is a precise 13th Century liturgical term for the Ancient Roman Rite, which is commonly termed the “Tridentine Mass” today.
St. Francis of Assisi can be rightly regarded as the “savior” of the Ancient Roman Rite, since, at the time of the foundation of his Order, on account of his desire to live the same religious life that the Apostles lived with Christ Jesus, the three years before He was Crucified and Died for our salvation, he petitioned Pope Innocent III to take as the rite of his Order, the ancient Rite of the Roman Church, which was held to be the “Rite of St. Peter the Apostle”. During the reign of Innocent III, this rite was only used on the Feast of the Chair of St. Peter, in the private papal Chapel, for the so-called Gallican Rite was universally employed in the Diocese of Rome. In addition only 3 known copies of the liturgical books of this ancient rite were still extant in 1215, one of which was falling to pieces. Pope Innocent III granted St. Francis’ request and gave him one of the good, still extant copies of the Sacramentum, Lectionary, Rituale and other books.
On account of the Rule of St. Francis, the Order of Friars Minor published the first Missale in 1245 — which was entitled the Missale Regulare — so that all the priests of the Order could easily fulfill their duties, without having to carry about these several liturgical books. Pope Innocent IV attempted to reform the liturgy of the Roman Church in the same year, a reform which was widely unpopular with the clergy of the Diocese of Rome by 1265 A.D..
And so by the reign of Pope Nicholas III, a close collaborator with St. Bonaventure of Bagnoregio, the pope having heard how well received the Missale Regulare of the Order was throughout all parts of Europe, on account of the great devotion of the Catholic Faithful to St. Peter the Apostle, decided to respond to the failed liturgical renewal of Innocent IV by establishing the Ancient Roman Rite once again as the proper rite of the Diocese of Rome.
This same Missale Regulare of 1245, which was adopted with very minor alterations for the calendar of the diocese clergy in 1265, was republished in 1465 as the curial missal. It was this Missale, that Pope St. Pius V, by his Bull Missale Romanum of 1570, established as the Missale Romanum, and imposed upon the entire Latin Rite in according with the mandate of the infallible, ecumenical Council of Trent, granting to all Roman Rite priests the perpetual privilege of celebrating the Holy Sacrifice of the Mass according to this Missal. The continued force of this privilege was confirmed by a commission of Cardinals in 1984 during the pontificate of Pope John Paul II. For this reason, every Franciscan priest of Order, has not only the right but even the duty of offering the Ancient Roman Rite whenever and wherever he may wish.
Today, this Ancient Roman Rite is eschewed and despised by many in the clergy and Order, on account of their lack of appreciation for the virtues of religion and for the importance of faith in Sacred Tradition and reverence for immemorial ecclesiastical traditions. We sons of St. Francis, today, must, more than ever, give a good, wholesome example of spiritual sobriety by returning to the liturgical patrimony of the Order. In this we will help in the most authentic and faithful way all men to approach the Most Holy Trinity with faith and penitence, hope and charity.
This article was taken from https://franciscan-archive.org/index2.html