Imad ad-Din Zengi was the son of Aq Sunqur al-Hajib, the governor of Aleppo under the Seljuk sultan Malik Shah. His father was executed for treason in 1094, and Zengi was raised by Kerbogha, the atabeg of Mosul. In 1127 Zengi seized power in Mosul after the death of Atabeg Toghtekin of Damascus and took Aleppo in 1128, and in 1136 he seized Baalbek. He gave Baalbek to Najm ad-Din, the father of Saladin, and in 1137 he seized Baarin from the Kingdom of Jerusalem after the Beylerbeylik of Damascus allied with Jerusalem against him. In 1138, he won a great victory at the Siege of Shaizar against the combined forces of the Byzantine Empire, Principality of Antioch, County of Edessa, and the Templar Order. On 24 December 1144, Zengi scored his greatest victory by taking Edessa, destroying the crusader state and leading to the Second Crusade being declared shortly after. In 1146 he was killed by slave Yarankash as he tried to conquer Damascus, putting an end to the spread of the Zengids.