"Ismat ad-Din" is a "laqab" (the descriptive part of an Arabic name) meaning "purity of the faith"; "Khatun" is an honorific meaning "lady" or "noblewoman". Her given name ("ism" in Arabic) is unknown. Her father became regent of Damascus in 1138, and ruled the city on behalf of a series of young emirs of the Burid dynasty. During this time, Damascus' chief rivals to the north, Aleppo and Mosul, were united under the rule of the Zengid dynasty. Damascus had maintained an unsteady alliance with the Crusader Kingdom of Jerusalem, but in 1147, Mu'in ad-Din negotiated an alliance with the Zengid emir of Aleppo, Nur ad-Din, who married Ismat ad-Din as part of the agreement. The next year, forces of Second Crusade conducted the unsuccessful Siege of Damascus, and Mu'in ad-Din was forced to recognize Nur ad-Din, who had come to his rescue against the crusaders, as overlord of the city. Ismat ad-Din Khatun's father died in 1149 and her husband gained complete control over Damascus by 1154.