Complex sentence: On November 12,1259, Al-Mansur Ali was deposed by Qutuz who became the new sultan promising the emirs that they could install any other sultan after he defeated the Mongols.
Split into simpler sentences: On November 12,1259, Al-Mansur Ali was deposed by Qutuz. When Qutuz became the new sultan, he promised the emirs that they could install any other sultan after he defeated the Mongols.