In the light of their attacks on Latin territory in 1241–4 and in 1259–60, the Mongols had emerged quite simply as the greatest threat confronting Catholic Christendom, so that in 1260 the Frankish leaders at Acre had chosen to cooperate with the more familiar Muslim demon as a means of staving off an attack by Hülegü's forces. The brief reign of Abaqa's brother and successor Tegüder, who had adopted Islam and assumed the style of Sultan Ahmad (1282–4), was marked by the opening of negotiations with Egypt. Ghazan, paradoxically, was a Muslim convert, having been induced to profess Islam by the prominent amir Nawruz, to whom he owed his enthronement, and very probably also by the spread of Islam within the ranks of the Mongol elite. A more extravagant development of this idea sees a Mongol–Frankish entente as administering such a blow to Islam that Christianity would have become and remained the dominant religion in the Near East.