Complex sentence: Following the murder in 1250 of Al-Muazzam Turanshah, the last Ayyubid sultan of Egypt, Damascus was seized by the Ayyubid ruler of Aleppo, An-Nasir Yusuf, leaving him in control of most of Syria until the arrival of the Mongols.
Split into simpler sentences: Following the murder in 1250 of Al-Muazzam Turanshah, the last Ayyubid sultan of Egypt, Damascus was seized by the Ayyubid ruler of Aleppo, An-Nasir Yusuf. He was in control of most of Syria until the arrival of the Mongols.