Following the death in 1128 of Toghtekin, atabeg of Damascus, a power vacuum threatened to open Syria to renewed Crusader aggression.Gabrieli 1969: 41 Zengi became atabeg of Mosul in 1127 and of Aleppo in 1128, uniting the two cities under his personal rule, and was formally invested as their ruler by the Sultan Mahmud II. Zengi had supported the young sultan against his rival, the caliph al-Mustarshid.
