The Mirdasids are members of the Banu Kilabi, an Arab tribe that had been present in northern Syria for several centuries.
Unlike other Arab tribes of Syria that managed to establish their autonomy or independence in the late tenth/early eleventh centuries, the Mirdasids had focused their energies on urban development.
As a result, Aleppo has prospered during their reign.
The Mirdasids demonstrate a high degree of tolerance to Christians, favoring Christian merchants in their territories and employing several as viziers.
This policy, no doubt influenced by comparatively good relations with the Christian East Roman Empire, often upsets the Muslim population.
The early history of the Mirdasid dynasty is characterized by constant pressure from both the Greeks of Constantinople and the Fatimids of Egypt.
By mixing diplomacy (the Mirdasids have been vassals of both the East Romans and Fatimids several times) and military force, the Mirdasids have been able to survive against these two powers.
Troubles with the Kilab had caused Amir Thimal to give up Aleppo to the Fatimids in exchange for several coastal towns.
The Kilab had thrown their support behind Thimal's nephew Rashid al-Daula Mahmud, who had taken Aleppo in 1060.
Thimal was in Cairo when he was informed by the caliph that his nephew had seized Aleppo, and as a result the caliph would be retaking the coastal provinces allotted to him.
Thimal had decided to return to Aleppo, but found Mahmud unwilling to yield control, while another Mirdasid, 'Atiyya ibn Salih, Thimal's brother, had become independent in Rahba.
After several military engagements between Thimal and Mahmud, the Kilab come up with a compromise.
Mahmud gives up Aleppo to his uncle, in exchange for cash and grain.
Thimal therefore reenters Aleppo in 1061.
