Alexios I soon took perhaps his most important action as Emperor when he called on Pope Urban II for help in combating the Muslims of Anatolia and the Levant. Alexios particularly hoped to recover Syria and other areas that had been part of the Byzantine Empire in previous centuries. He succeeded in his attempt to rally Western European support, as a surprisingly large contingent of crusaders under Godfrey of Bouillon (among other European nobles) set off from Western Europe and journeyed through Anatolia all the way to their eventual destination of Jerusalem. While relations between crusaders and Byzantines were not always cordial, the coordination between the two armies was instrumental in capturing many important cities in Asia Minor and eventually Jerusalem itself. Between 1097 and 1101 Alexios managed to recover Nicaea, Rhodes, and Ephesus, while also making Antioch his vassal. This brought the Empire to its largest extent since before Manzikert in 1071.