Nūr al-Dīn Maḥmūd Zengī (نور الدين محمود زنگي; February 1118 – 15 May 1174), commonly known as Nur ad-Din (lit.

[3] Nur ad-Din was the second son of Imad al-Din Zengi, the Turkoman atabeg of Aleppo and Mosul,[4] who was a devoted enemy of the crusader presence in Syria.

Almost as soon as he began his rule, Nur ad-Din attacked the Principality of Antioch, seizing several castles in the north of Syria, while at the same time he defeated an attempt by Joscelin II to recover the County of Edessa, which had been conquered by Zengi in 1144.

Nur ad-Din's victories and the Crusaders' losses in Asia Minor however had made the recovery of Edessa – their original goal – practically impossible.

He did not, however, attack Antioch itself; he was content with capturing all Antiochene territory east of the Orontes and leaving a rump state around the city, which in any case soon fell under the suzerainty of the Byzantine Empire.

In the Battle of Aintab, Nur ad-Din tried but failed to prevent King Baldwin III of Jerusalem's evacuation of the Latin Christian residents of Turbessel.

Damascus was annexed to Zengid territory, and all of Syria was unified under the authority of Nur ad-Din, from Edessa in the north to the Hauran in the south.

Nur ad-Din was generous in his victory, and allowed Abaq to flee with his property, later granting him fiefdoms in the vicinity of Homs.

[7] He was cautious not to attack Jerusalem right away, and even continued to send the yearly tribute established by Mujir ad-Din; meanwhile he briefly became involved in affairs to the north of Mosul, where a succession dispute in the Sultanate of Rum threatened Edessa and other cities.

[citation needed] In 1157, Nur ad-Din besieged the Knights Hospitaller in the crusader fortress of Banias, routed a relief army from Jerusalem led by King Baldwin III, and captured Grand Master Bertrand de Blanquefort.

In 1159, the Byzantine emperor Manuel I Comnenus arrived to assert his authority in Antioch, and the crusaders hoped he would send an expedition against Aleppo.

[7] By 1162, with Antioch under nominal Byzantine control and the crusader states further south powerless to make any further attacks on Syria, Nur ad-Din made a pilgrimage to Mecca.

Soon after he returned, he learned of the death of King Baldwin III of Jerusalem, and out of respect for such a formidable opponent he refrained from attacking the crusader kingdom: William of Tyre reports that Nur ad-Din said "We should sympathize with their grief and in pity spare them, because they have lost a prince such as the rest of the world does not possess today.

Nur ad-Din's attack on Tripoli was unsuccessful, but he was soon visited by the exiled Shawar, who begged him to send an army and restore him to the vizierate.

Nur ad-Din did not want to spare his own army for a defense of Egypt, but his Kurdish general Shirkuh was given permission to invade in 1164.

Shirkuh agreed to abandon Egypt when Amalric was forced to return home, after Nur ad-Din attacked Antioch and besieged the castle of Harenc.

[7] In the same year, Nur ad-Din raided the County of Tripoli, in which he temporarily captured Areimeh Castle, Chastel Blanc and Gibelacar, exploiting the captivity of Raymond III.

With Egypt conquered in his name, Nur ad-Din believed that he had accomplished his goal of uniting the Arab states of the Levant.

Nur ad-Din began preparations to invade Egypt and depose Saladin,[7] but he was seized by a fever due to complications from a peritonsillar abscess.

[7] According to William of Tyre, although Nur ad-Din was "a mighty persecutor of the Christian name and faith," he was also "a just prince, valiant and wise, and according to the traditions of his race, a religious man."

[22] His repair of the Roman aqueduct in Aleppo insinuated an anti-Shia polemic,[23] and the conversion of two Shia mosques into madrasas, one Shafi'i another Hanafi, reinforce his insistence of promoting Sunni Islam.

The Islamist group Harakat Nour al-Din al-Zenki, active in the Syrian Civil War in Aleppo since 2011, is named after Nur ad-Din.