The Fourth Crusade (1198–1204), which some historians call the fifth, was authorised by Pope Innocent III., and preached in France by the celebrated Foulques de Neuilly. This crusade was remarkable in one respect. Its efforts at first were directed against the persecutors of Christianity, but events, as they developed themselves, modified its aim, and the question of the holy places having become abandoned, it ended, after the taking of Constantinople (Fig. 106), in the overthrow of the dynasty of the successors of Constantine, and its being replaced by a French dynasty, the founders of the Latin Empire of Byzantium. Following the example of Baudouin, Count of Flanders, the principal nobles of the crusading army divided among themselves the spoils of the Greek Empire, and ceased to think of the holy war. In 1217, Andrew, King of Hungary, in company with several nobles of Germany and France, assumed the cross. This expedition sailed for Egypt, and laid siege to Damietta, which only capitulated after losing eighty thousand of its inhabitants. From thence it moved on to Cairo, but, being decimated by the plague, it was forced to retreat and return to Europe. This was really the fifth crusade. [Illustration: Fig. 106.--Second taking of Constantinople, in 1204.--From a Fresco by Tintoretto, in the Palace of the Doges, Venice (Sixteenth Century).] In 1228, Frederick II., King of Naples and Sicily, having been elected Emperor of Germany, conceived the idea, more from political than religious motives, of reconquering, in the name of Christendom, the Holy City. He embarked, accompanied only by a few hundred soldiers, and, landing in Egypt, had an interview with the Sultan, who was persuaded, under some unknown influence, to sign a treaty, by virtue of which Nazareth, Bethlehem, and Jerusalem were to be restored to the Christians, under the express condition that the Mussulmans should be allowed to retain the Temple and to erect a mosque in the city of Jesus Christ. This was at best a sacrilegious compact. It was neither approved nor kept by the Christians or by the Saracens, and was soon considered by Frederick himself a worthless compromise, although he had entered Jerusalem in person, and had there crowned himself with his own hands. This singular expedition was termed the Sixth Crusade.