Nur ad-Din ruled as Zengid emir of Damascus from 1154 until his death in 1174. He took up residence in the citadel and rebuilt or refurbished its residential structures. After an earthquake hit Damascus in 1170, Nur ad-Din built a wooden house for sleeping and prayer next to the original stone residence of the citadel. In addition, he built a mosque and a fountain in the citadel. Between 1165 and 1174, Nur ad-Din re-fortified Damascus with a concentric wall, and it is possible that he also strengthened the defences of the citadel. Nur ad-Din died of an illness in the citadel on 15 May 1174 and was buried there; his body was later transferred to the Nur ad-Din Madrasah in Damascus.