Middle Egypt. Before the Banu Kanz could link with Abbas, Saladin's forces under Abu al-Hayja's command defeated and killed Abbas. The Ayyubid army proceeded to confront the Banu Kanz, who were defeated after major clashes in Aswan. Ibn al-Mutawwaj was eventually captured and executed in the aftermath of his army's defeat. The expulsion of the Banu Kanz from the frontier zone around Aswan caused the area's neglect, including the greatly reduced exploitation of the mines and the increased vulnerability of travelers and caravans to Bedouin raids, due to the absence of the Banu Kanz, the region's traditional guardians. With the loss of their capital, the Banu Kanz migrated south to occupy Maris, where Nubian control of the region had been significantly diminished due to the Ayyubid punitive expedition in 1172. While the Banu Kanz assimilated into the Nubian culture and language, their way of life remained Islamic. The presence of the Banu Kanz in Maris significantly contributed to the spread of Islam and the Arabic language in Nubia. Domination of Makuria and relations with the Mamluks In 1317, the Mamluk sultan an-Nasir Muhammad (the Mamluks succeeded the Ayyubids in Egypt in 1250) maneuvered to install a puppet Muslim pretender, Barshanbu, as king of Christian Makuria, to replace King Karanbas. The latter sought to avoid his deposition by sending an-Nasir Muhammad the Kanz al-Dawla, who was a nephew of Karanbas, as a potential Muslim replacement instead of Barshanbu. Karanbas viewed the Kanz al-Dawla as more tolerable and potentially cooperative than Barshanbu. However, the Kanz al-Dawla was arrested by the Mamluks upon his arrival to Cairo and the Mamluks successfully installed Barshanbu as king. The latter subsequently made Islam the religion of Makuria. The Kanz al-Dawla was released shortly thereafter and usurped the throne, prompting an-Nasir Muhammad to launch two unsuccessful expeditions against the Banu Kanz (the last occurring in 1324), and the Kanz al-Dawla held onto the Makurian throne. During the reign of Sultan al-Ashraf Sha'ban and regent Yalbugha al-Umari, the Banu Kanz and their Arab ally, the Banu Ikrima, were in control of the region between the Red Sea ports of Aydhab and Suakin in the east and the Nile River banks to the west. The Mamluks sent an expedition against the Banu Kanz and Banu Ikrima after Dongola was captured by the tribesmen and its king killed. The Kanz al-Dawla and other Banu Kanz chiefs surrendered to the Mamluk