In 1186, when az-Zahir was 15 years of age, his father appointed him governor of Aleppo, Mosul and supporting areas which had recently been taken from the Zengids.

[3] He brought the unorthodox as-Suhrawardi to Aleppo, but was forced to imprison him in 1191 due to the demands of the orthodox ulama ("men of learning").

Early in the next year, while al-Adil was in the north suppressing an Artuqid rebellion, al-Afdal and az-Zahir came together in alliance and were joined by most of the other Ayyubid princes.

In 1206, King Leo of Cilicia defeated az-Zahir forces at the Battle of Amq, but was unable to secure any permanent advantage against Aleppo.

In 1207, the French attacked and besieged Homs and its emir, an Ayyubid prince called Mujadid Shirkuh II, appealed to az-Zahir, whose troops lifted the siege.