Overview
An-Nasir Yusuf (; AD 1228–1260), fully al-Malik al-Nasir Salah al-Din Yusuf ibn al-Aziz ibn al-Zahir ibn Salah al-Din Yusuf ibn Ayyub ibn Shazy, was the Ayyubid Kurdish Emir of Syria from his seat in Aleppo (1236–1260), and the Sultan of the Ayyubid Empire from 1250 until the sack of Aleppo by the Mongols in 1260.
Background
An-Nasir Yusuf was the great-grandson of Saladin. He became the Ayyubid ruler of Aleppo when he was seven-years-old after the death of his father Al-Aziz Muhammad. He was placed under a four-man regency council, consisting of the vizier Ibn al-Qifti, the emir Shams al-Din Lu'lu' al-Amini, the emir 'Izz al-Din 'Umar ibn Mujalli and Jamal al-Dawla Iqbal. The last was the representative of an-Nasir's grandmother, Dayfa Khatun, daughter of Al-Adil I, who was the effective ruler until her death in 1242. Thereafter until his death in 1251, Shams al-Din was an-Nasir's commander-in-chief and most influential advisor. His most loyal troops were the Qaymariyya, upon whose emirs he relied heavily for advice.
Conflict with Egyptian Mamluks
In 1250, when the Ayyubid sultan of Egypt as-Salih Ayyub died and his son Turanshah was murdered by the Bahri Mamluks of Egypt, Shajar al-Durr (widow of as-Salih Ayyub ) seized the throne of Egypt. An-Nasir Yusuf, being an Ayyubid, refused to recognize Shajar al-Durr as the Sultana of Egypt and, as a sign of support, the Emirs of Syria granted him the city of Damascus, in Syria.
Alarmed by these developments, the Mamluk leaders in Egypt decided to replace Shajar al Durr with the Atabek (commander in chief) Aybak. In October 1250, An-Nasir Yusuf sent forces to Gaza to conquer Egypt and overthrow Aybak, but Egyptian forces led by Faris ad-Din Aktai defeated them.
From Wikipedia (CC BY-SA 4.0).