The text of the Later Rule or Regula bullata (RegB) was officially approved by Pope Honorius III on 29 November 1223. The RegB is the Rule which all male Franciscans of the OFM, OFMConventual and OFM Capuchin families of the First Order profess.

The original of the RegB is treasured as a precious relic in the lower basilica of St. Francis in Assisi. The text is a proof that this Rule is included in a papal Bull, thus indicating that the Church considers the Franciscan way of life as wholly Catholic.

The circumstances which refer to the writing of this Rule are given by various sources. St. Bonaventure (Legenda Maior IV,11) says that Francis withdrew to a high place and dictated the Rule. Elias, his vicar, later said that he lost the Rule, and so Francis retreated again to this lonely spot (hermitage of Fontecolombo) to write the Rule all over again. The symbolism Moses-Christ-Francis, and Commandments-Beatitudes-Rule, is evident. Later sources went even so far as stating that the Rule was personally dictated to Francis by Christ himself.

Francis asked two friars to help him to write the Rule, namely Leo and Bonizo from Bologna, an expert in canon law. The Rule also betrays the influence of Cardinal Hugolino.

The RegB is divided into 12 chapters, even though this division is not found in the original version. It is altogether a concise document, in which the trend at forming a legislative code for the Order is not absent. The first chapter simply states that the Rule and Life of the Friars Minor is that of living the Gospel. For Francis these words were more than enough to express his ideals.