ʿIṣmat ad-Dīn Khātūn ( عصمة الدين خاتون; died January 26, 1186), also known as Asimat, was the daughter of Mu’in ad-Din Unur, regent of Damascus, and wife of two of the greatest Muslim generals of the 12th century, Nur ad-Din Zangi and Saladin.
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) 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, the Second Crusade besieged 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.
When Nur ad-Din died in 1174, King Amalric I of Jerusalem took advantage of the situation and besieged the city of Banias. Ismat offered him a bribe to lift the siege, but, hoping for a larger offer, Amalric continued the siege for two weeks, until finally accepting the money along with the release of twenty Christian prisoners. William of Tyre describes Ismat as having “courage beyond that of most women” in this matter. Nur ad-Din’s general Saladin had meanwhile gained control over Egypt, and claimed Damascus as his successor; he legitimized this claim by marrying Ismat at-Din in 1176. She was apparently not his only wife. However, by the time she died in 1186, Saladin was writing letters to her every day; as he was himself recovering from a lengthy illness at the time, news of her death was kept from him for three months.
She had no children with either Nur ad-Din or Saladin. In Damascus she was the patron of numerous religious buildings, including a madrasa and a mausoleum for her father. She was buried in the Jamaa’ al-Jadid in Damascus.