His order multiplied rapidly, and convents were established in all parts of Europe; although he was inclined to object to costly buildings, and was prevailed upon to let them stand on the plea that they were needed to shelter travellers and pilgrims. He established also the order of Poor Clares, so called from a noble maiden, Clare, who became its first superior. This was, for women, what his order of the Friars Minor was for men; though the Clares remained strictly enclosed, while the Friars went abroad preaching, and established missions in various quarters of the globe. Finally, he formed his Third Order, which included laymen and laywomen living in the world, who bound themselves by simple vows of virtue and charity, while continuing in their accustomed phase of life. Thousands joined the Friars; and probably millions were enrolled in the Third Order. It has been said that Francis first made known to the Middle Ages the power of association among the weak and humble, and that from the pages on which he inscribed his institutes sprang modern democracy in Italy. Certain it is that the Emperor Frederick II. received a letter from some of his Italian feudal supporters, saying: "The Friars Minor ... have raised themselves against us. They have publicly condemned both our mode of life and our principles, they have shattered our rights, and have brought us to nothingness." Yet the Franciscan Friars and the Third Order had done this only by the contrast of example, of poverty, fasting, prayer, self-denial, and charity of the heart as well as of the hands. The work of Saint Francis did much to undermine feudalism; and it almost regenerated the spirit of Christianity in the thirteenth century. "Man of the people," writes R. F. O'Connor, "he did more for the people than ever yet had been done by any one; whose vocation was to revive in the midst of a corrupting opulence the esteem and practice of poverty, which he ennobled, ... and, without setting class against class, _or violating the least point of the divine or human law_, levelled every social barrier and united princes and peasants in a bond of union which neither time nor eternity was to sever."