The quarrel with the papacy was continued with the new pope Urban III., and open warfare was begun. But Frederick was soon recalled to Germany by the news of a revolt raised by Philip of Heinsberg, archbishop of Cologne, in alliance with the pope. The German clergy remained loyal to the emperor, and hostilities were checked by the death of Urban and the election of a new pope as Gregory VIII., who adopted a more friendly policy towards the emperor. In 1188 Philip submitted, and immediately afterwards Frederick took the cross in order to stop the victorious career of Saladin, who had just taken Jerusalem. After extensive preparations he left Regensburg in May 1189 at the head of a splendid army, and having overcome the hostility of the East Roman emperor Isaac Angelus, marched into Asia Minor. On the 10th of June 1190 Frederick was either bathing or crossing the river Calycadnus (Geuksu), near Seleucia (Selefke) in Cilicia, when he was carried away by the stream and drowned. The place of his burial is unknown, and the legend which says he still sits in a cavern in the Kyffhaeuser mountain in Thuringia waiting until the need of his country shall call him, is now thought to refer, at least in its earlier form, to his grandson, the emperor Frederick II. He left by his wife, Beatrix, five sons, of whom the eldest afterwards became emperor as Henry VI. Frederick's reign, on the whole, was a happy and prosperous time for Germany. He encouraged the growth of towns, easily suppressed the few risings against his authority, and took strong and successful measures to establish order. Even after the severe reverses which he experienced in Italy, his position in Germany was never seriously weakened; and in 1181, when, almost without striking a blow, he deprived Henry the Lion of his duchy, he seemed stronger than ever. This power rested upon his earnest and commanding personality, and also upon the support which he received from the German church, the possession of a valuable private domain, and the care with which he exacted feudal dues from his dependents.