of the ordinance[83] that those who took up the Cross should be freed from all engagements to pay usury into which they might have entered. Innocent III. absolved Crusaders even from obligations of the kind that they had incurred under oath, and subsequently ordered that Jews should be forced, under penalty of exclusion from the society of Christians, to return to their crusading debtors any interest that they had already received from them.[84] Stronger even than the influence of the Crusades was that of the Mendicant Orders. The Dominicans, who preached, and the Franciscans, who “taught and wrought” among all classes of people throughout Europe, carried with them, as their most cherished lesson, the doctrine of poverty. It was by the teaching of this doctrine, and by the practice of the simple unworldly life of the primitive Church, that the founders of the two orders had been able to give new strength to the ecclesiastical institutions of the thirteenth century. And their teaching, if not their practice, made its way from the Casiuncula to the Vatican. Cardinal Ugolino, the dear friend of S. Francis, became Gregory IX.; Petrus de Tarentagio, of the order of the Dominicans, became Innocent IV.; and Girolamo di Ascoli, the “sun” of the Franciscans, was soon to become Nicholas IV. Moreover, the work of formulating and publishing to the world the official doctrines of the Church was in the hands of the Mendicants. A Dominican, Raymundus de Peñaforte, was entrusted by Gregory IX. with the preparation of the Decretals, which formed the chief part of the canon law of the Church.[85] And friars of both orders codified with indefatigable labour the moral law of Christianity, and set it forth in hand-books, or _Summæ_, which were universally accepted as guides for the confessional, and which all agreed in condemning usury.[86] Hence, the doctrine of its sinfulness was taught throughout Christian Europe, by priests and monks, by Dominican preachers and Franciscan confessors, who could enforce their lesson by the use of their power of granting or refusing absolution. How strong and violent a public opinion was thus created is best shown in the lines in which Dante, the contemporary of Edward I., tells with what companions he thought it fit that the Caursine usurers should dwell in hell.[87]