 Aleppo underwent major transformations in the Ayyubid period, specifically during the reign of az-Zahir Ghazi. Ayyubid architectural achievements focused on four areas: the citadel, the waterworks, fortifications, and the extramural developments. The total rebuilding of the city enclosure began when az-Zahir Ghazi removed the vallum of Nur ad-Din — which by then outlived its temporary need — and rebuilt the northern and northwestern walls — the most susceptible to outside attack — from Bab al-Jinan to Bab al-Nasr. He parceled out the building of the towers on this stretch of the wall to his princes and military officers; each tower was identified with a particular prince who inscribed his name into it. Later, az-Zahir Ghazi extended the eastern wall to the south and east, reflecting his desire to incorporate a dilapidated fortress, Qala 'at al-Sharif, outside the city into Aleppo's enclosure. Bab Qinnasrin was completely rebuilt by an-Nasir Yusuf in 1256. This gate stands today as a masterpiece of medieval Syrian military architecture. Cumulatively, Ayyubid architecture left a lasting impression in Aleppo. The citadel was rebuilt, the water network was expanded, and streets and quarters were provided fountains and baths. In addition, dozens of shrines, mosques, madrasas, and mausoleums were built throughout the city.
