sentences:  In 1253, through mediation of some Emirs, an accord was reached between an-Nasir Yusuf and 
  Aybak which gave the Egyptians control over Gaza, Jerusalem, Nablus, and the coastline of al-Sham.In 1254, another power shift occurred in Egypt, as Aybak killed Faris ad-Din Aktai, the leader of the Bahri Mamluks.Some of his Mamluks, among them Baibars al-Bunduqdari and Qalawun al-Alfi, fled to an-Nasir Yusuf in Syria, persuading him to break the accord and invade Egypt.