In 1153 Ascalon was lost, the last place in Syria which the Fatimids held; its loss was attributed to dissensions between the parties of which the garrison consisted. In April 1154 the Caliph al-Zafir was murdered by his vizier Abbas, according to Usamah, because the Caliph had suggested to his favorite, the vizier's son, to murder his father; and this was followed by a massacre of the brothers of Zafir, followed by the raising of his infant son Abul-Qasim Isa to the throne.