 Intent on restoring the supremacy of Saladin 's direct descendants within the Ayyubid family , an @-@ Nasir Yusuf was eventually able to enlist the backing of all of the Syria @-@ based Ayyubid emirs in a common cause against Mamluk @-@ dominated Egypt . By 1250 , he took Damascus with relative ease and except for Hama and Transjordan , an @-@ Nasir Yusuf 's direct authority stood unbroken from the Khabur River in northern Mesopotamia to the Sinai Peninsula . In December 1250 , he attacked Egypt after hearing of al @-@ Mu 'azzam Turan @-@ Shah 's death and the ascension of Shajar al @-@ Durr . An @-@ Nasir Yusuf 's army was much larger and better @-@ equipped than that of the Egyptian army , consisting of the forces of Aleppo , Homs , Hama , and those of Saladin 's only surviving sons , Nusrat ad @-@ Din and Turan @-@ Shah ibn Salah ad @-@ Din . Nonetheless , it suffered a major defeat at the hands of Aybak 's forces . An @-@ Nasir Yusuf subsequently returned to Syria , which was slowly slipping out of his control . 
