As known, Saint Francis founded three orders and gave each of them a special rule. Here, only the rule of the first order is to be considered, i.e., that of the Order of Friars Minor.
There are, as in so many other points in the life of St. Francis, not a small amount of doubt and controversy about the Rule of St. Francis. Whether St. Francis wrote several rules or one rule only, with several versions, whether he received it directly from heaven through revelations, or whether it was the fruit of his long experiences, whether he gave it the last touch or whether its definite form is due to the influence of others, all these are questions which find different answers. However in some cases, it is more a question of words than of facts. We may speak of three successive rules or of three successive versions of the same rule; that makes little difference, since the spirit in the three cases are the same. For clearness, we shall speak simply of the three rules, the first of which is of the year 1209, the second of 1221, the third of 1223; expounding more especially the one of 1223, as this is properly the Rule of St. Francis, the object of this article.
This is the rule St. Francis presented to Innocent III for approval in the year 1209; its real text is not known. If, however, we regard the statements of Thomas of Celano (I Cel., i, 9 and 13, ed. d'Alencon, Rome, 1906) and St. Bonaventure (Legenda major, c. iii), we are forced to conclude that this primitive rule was little more than some passages of the Gospel heard in 1208 in the chapel of Portiuncula. From which Gospel precisely these words were taken, we do not know. The following passages, Matthew 19:21; Matthew 16:24; Luke 9:3, occurring in the second rule (i and xiv), are considered as a part of the original one of 1209. They enjoin apostolical life with all its renouncements and privations. The three vows of obedience, chastity, and poverty, essential to any religious order, and some practical rules of conduct were added. Thomas of Celano says in this regard (I Cel., i, 13): "Blessed Francis, seeing that the Lord God was daily increasing the number [of the brethren] for that very purpose, wrote down simply and in few words for himself and for his brethren, both present and future, a pattern and rule of life, using chiefly the language of the holy Gospel after whose perfection alone he yearned" [version of Ferrers Howell (London, 1908), p. 31]. St. Bonaventure (loc. cit.) and the so-called "Legend of the Three Companions" (viii) repeat almost the same words. The fact can otherwise be gathered from the description of the early state of the order, made by St. Francis himself in the "Testament": "And when the Lord gave me some brothers, no one showed me what I ought to do, but the Most High Himself revealed to me that I should live according to the form of the holy Gospel. And I caused it to be written in few words and simply, and the Lord Pope confirmed it for me" (version of Paschal Robinson). These last words of St. Francis refer to the oral approval of the original rule, given by Innocent III, 1209. Angelo Clareno, in his (not printed) "Exposition of the Rule," alleges that this rule was approved in the Fourth Lateran Council, 1215. But this is not certain; it is not even proved that St. Francis was in Rome at that time. Still, indirectly, Angelo Clareno is right, inasmuch as the prohibition of founding new orders, decreed at this council, was not applied to St. Francis's institute. Some letters of Honorius III, given 1219 (Bullarium Franciscanum, I, 2), may also be considered as a general approbation of the life and rule of the friars. The text of the primitive rule seems to have perished very early, since Hugo of Digne (Expositio in Regulam, Prologus and c. xii) in the middle of the thirteenth century, Ubertino of Casale (Arbor Vitae, Bk. V, c. v, Venice, 1485, f.E.II, v., a) and Angelo Clareno (Expositio in Regulam, passim) in the beginning of the fourteenth century, quote constantly as the first rule, confirmed by Innocent III, the one written in 1221. However, endeavours of reconstruction have been made by Karl Mueller (Die Anfaenge des Minoritenordens und der Bussbruderschaften, Freiburg im Br., 1885, 185-188), and by H. Böhmer (Analekten zur Geschichte des Franciscus von Assisi, Tuebingen and Leipzig, 1904, 88-89). This first rule marks the stage of the order governed by St. Francis's personal authority, and it is quite natural that this first attempt could not be developed as later rules were. But to conclude hence that Francis did not intend to found an order properly so called, in other words, to write any religious rule at all, is quite different. All that can be said is this, that St. Francis did not take as his model any monastic order, but simply the life of Christ and His Apostles, the Gospel itself.