Ubertinus surnamed, from the village of his birth, De Casali, was a Franciscan monk of the 13th century, and belonged to the strict party which insisted upon a rigid observance of the vow of poverty, and regarded the life and work of our Savior as constituting a mere preparation for a higher and more perfect era of the Holy Ghost. They also denounced the condition of the papacy and of the entire Church as being utterly corrupt. Ubertinus was a pupil of Peter John Olivi (died 1297), who stood at the head of his party. He defended the tenets of his party in an apology for Olivi, which .is given in Wadding, Annales Minorum, etc. (Romse, 1733; ann.1297), 36:380 sq., and was severely assailed. Pope Clement V and many others called him to account for his book, and Ubertinus thereupon resolved to sever his connection with his order. Pope John XXII permitted him to enter the Benedictine convent of St. Peter at Gemblours; but the monks refused to receive him, and it is said that he ultimately became a Carthusian in the meantime, pope John had again demanded an explanation of his opinions respecting the poverty of Jesus, etc., and Ubertinus responded that Jesus could not be said to have had possession of property in any secular meaning of the words (see Wadding, ut sup. 6:362 sq.). In addition to the above, Ubertinus wrote a sort of commentary on the Apocalypse, entitled Tractatus de Septema Statibus Ecclesiae (Venet. 1516). The time and manner of his death are unknown. See Herzog, Real-Encyklop. s.v.