In addition to the conflict with the Ayyubids of Syria, the Mamluks successfully countered serious rebellions in Middle and Upper Egypt. Then, Aybak, fearing the growing power of the Salihiyya Mamluks who, with Shajar al-Durr, had installed him as a Sultan, had their leader Faris ad-Din Aktai murdered. The murder of Aktai was followed instantly by a Mamluk exodus to Syria where they joined the Ayyubid an-Nasir Yusuf. Prominent Mamluks like Baibars al-Bunduqdari and Qalawun al-Alfi were among those Mamluks who fled to Syria. Aybak became the sole and absolute ruler of Egypt after the Salihiyya Mamluks who were the supporters of Shajar al-Durr left Egypt and turned against him.