The Crusaders assembled in Apulia had much to suffer from the influences of the climate and the season; the sovereign pontiff neglected nothing to alleviate their distresses and hasten their departure. He exhorted the emperor to embark, by saying to him, “The Lord has placed you in this world as a cherubim with a flaming sword, to direct those who stray from the way of the tree of life.” Frederick at length yielded to the prayers of the pope, and sailed from the port of Brindisi with his fleet and army. Prayers were being put up for the prosperity of his voyage and the success of his expedition, in all the provinces of his empire, when, at the end of three days, being attacked by the malady that had made such ravages in the Christian army, he retraced his course, and landed in the port of Otranto. Gregory had celebrated the departure of Frederick as a triumph of the Church; he considered his return as an absolute revolt against the Holy See. The little city of Agnani, to which the pope had retired, witnessed the rage of the pontiff, and beheld the birth of that formidable storm which so long disturbed the Christian world. Accompanied by the cardinals and several bishops, Gregory repaired to the principal church, and having mounted the pulpit, before the assembled people, he pronounced a sermon which had for its text, “It is necessary that scandals should arise.” After having called upon the prophets, and spoken of the triumph of St. Michael over the dragon, he launched against Frederick all the anathemas of the Church. The emperor at first sent messengers to the pope to explain and justify his conduct; but the inexorable Gregory refused to listen to them, and complained to all the sovereigns of Europe, representing Frederick as a faithless and perjured prince. He accused him of having consigned his wife Yolande to close imprisonment, in which she died of grief; of having left the Crusaders to perish with hunger, thirst, and heat in the plains of Apulia; and of having, at last, under the frivolous pretext of sickness, violated his oath and deserted the banners of Christ, _in order to return to the customary enjoyments of his kingdom_. He made him many other reproaches; and in his anger called down upon him the maledictions of all Christians.