Ayyubid Military Fortifications in the Lands of Egypt and Syria

Salah al-Din Youssef ibn Nagm al-Din Ayyub ibn Shady is an orthodox Sunni Muslim, to whom the Ayyubid state attributed, his family was a decedent of the Kurdish, originated in a town called Doween in Alkr).
His position in Egypt was far from secure. As the general of Nur al-Din, holding Cairo by force of Zangid arms, he was regarded with deep suspicion by the Fatimids, who tried to oust the inexperienced young vizier by encouraging a revolt of their Sudanese palace guards. The insurrection was easily crushed, however, leaving the Fatimids with no pretense of military support. Salah al-Din then abolished Fatimid rule in 1171 A.D, reintroducing Sunni Islam as the official religion of Egypt. The surviving Fatimid princes and princesses were carefully segregated and placed in honorable captivity to prevent the birth of a future claimant to a universal Shiite state. Al-Qahira was deprived of its royal status and opened shift northward followed, resulting, in al-Fustat's losing its position as Egypt's major center of trade and production.