Saif ad-Din Ghazi I was the eldest son of Zengi of Mosul, and the elder brother of Nur ad-Din. After the death of Zengi in 1146 Saif ad-Din succeeded his father in Mosul and the Jezirah (northern Iraq) while Nur ad-Din succeeded in Aleppo. In 1148 he marched south to help defend Damascus during the Second Crusade. He died in November 1149 and was succeeded by another brother, Qutb ad-Din Mawdud .

See also Zengid dynasty.