The Exilarchate in Mesopotamia was officially restored after the Arab conquest in the 7th century and continued to function during the early Caliphates. Exilarchs continued to be appointed until the 11th century, with some members of the Davidic line dispersing across the Islamic world. There are conflicting accounts of the fate of the Exilarch family in the 11th century; according to one version Hezekiah ben David, who was the last Exilarch and also the last Gaon, was imprisoned and tortured to death. Two of his sons fled to Al-Andalus, where they found refuge with Joseph, the son and successor of Samuel ibn Naghrillah. However, "The Jewish Quarterly Review" mentions that Hezekiah was liberated from prison, and became head of the academy, and is mentioned as such by a contemporary in 1046. An unsuccessful attempt of David ben Daniel of the Davidic line to establish an Exilarchate in the Fatimid Caliphate failed and ended with his downfall in 1094.