The second object which Gregory VII. had in view, was the preservation of Christian civilisation from the Mussulman yoke, by carrying the war into the East; and the Crusades realised this great design. We may now sketch in a few lines the part played by the popes during the last centuries of the Middle Ages. [Illustration: Fig. 213.--Gregory IX. (1227–1241) handing the _Decretals_, which he had embodied in one work, to an advocate of the Consistory.--Fresco by Raphael (1515), in the _Stanzas_ at the Vatican.] The great Roman families, anxious to obtain power, elected an anti-pope. By means of these agitations, Arnold of Brescia, under the pretext of creating a Roman republic, established a kind of dictatorship in the city. The emperor overthrew this usurper, who was burnt alive; but he set up anti-popes, and Alexander III., when besieged in Rome, declared himself the ally of the Lombard cities, the chief of the Guelfs against the Ghibelins, and the champion of Italian liberty. Under his pontificate, it was ordained (at the third Council of the Lateran, in 1179, that for the future, the cardinals alone should take part in the election for the pontiff, without the intervention of the clergy or the people. The Crusades occupied men’s minds during the last twenty years of the twelfth century. The thirteenth began with one of the most celebrated of the popes, Innocent III., who, following in the footsteps of Gregory VII., made emperors and kings to tremble by his threats of excommunication, and preached the crusade against the infidels and the Albigenses. His two successors, Honorius III. and Gregory IX., imitated his zeal and resolution. Gregory IX., amidst the multifarious cares of his holy office, found time to draw up a new collection of his own letters and constitutions, and those of his predecessors. He confided this heavy task, which was carried out with remarkable skill and order, to Raymundus de Pennaforti, his chaplain. This collection, which was received with respectful gratitude, has since been called the _Decretals_ (Fig. 213). After these three eminent popes, sedition broke out afresh inside Rome. The Holy See was vacant for a long period more than once during the latter part of this century, as the cardinals could not agree in their choice; and in consequence it was decided that the election should take place in conclave. After a numerous series of popes, who occupied the chair for only a short time, Boniface VIII. (Fig. 218) endeavoured to march in the footsteps of Gregory VII. and Innocent III. Philippe le Bel, anxious to destroy all traces of the feudal régime in order to obtain absolute power, would not submit to the reprimands and menaces of the pope, and it is well known how he caused the pontiff to be seized at Anagni by Nogaret. The aged pontiff, whom nothing could move, was set free by the people, who expelled Nogaret and his soldiers; but the rough treatment he had received hastened his death.