 Complete the following phrase:  Throughout the Ayyubid and Mamluk periods, al-Rahba was situated near the tribal territory of the Al Fadl. About four hundred Al Fadl tribesmen joined the small army of Caliph al-Mustansir, the Egypt-based Abbasid caliph dispatched by Baybars to recapture Baghdad from the Mongols, when he reached al-Rahba. The latter was al-Mustansirs first stop after he rode out from Damascus, but his campaign ultimately failed and he was killed in a Mongol ambush in al-Anbar. The Mongols of Ilkhanid Iraq inflicted significant damage on al-Rahba during their 