William's foresight about the misfortunes of his country was proven correct less than a year later. Saladin defeated King Guy at the Battle of Hattin in 1187, and went on to capture Jerusalem and almost every other city of the kingdom, except the seat of William's archdiocese, Tyre. News of the fall of Jerusalem shocked Europe and plans were made to send assistance. According to Roger of Wendover, William was present at Gisors in France in 1188 when Henry II of England and Philip II of France agreed to go on crusade: "Thereupon the king of the English first took the sign of the cross at the hands of the Archbishop of Rheims and William of Tyre, the latter of whom had been entrusted by our lord the pope with the office of legate in the affairs of the crusade in the western part of Europe." Roger was however mistaken; he knew that an unnamed archbishop of Tyre was present and assumed it must have been the William whose chronicle he possessed, although the archbishop in question was actually William's successor Joscius.