The chosen successor of the Mirdasids' founder, his father Salih ibn Mirdas, Thimal was ousted from Aleppo by his brother Nasr in 1030, but retained the Jaziran (Upper Mesopotamian) half of the emirate from his seat in al-Rahba.
Nevertheless, financial and political conditions and dissent amongst his tribe, the Banu Kilab, the Mirdasids' core troops, compelled Thimal to abdicate in 1057 and retire to Cairo.
Thimal was a son of Salih ibn Mirdas, the paramount emir (prince) of the Banu Kilab who founded the Mirdasid dynasty whose territories encompassed the region of Aleppo and the western Jazira.
When Salih was slain by the forces of the Fatimid general Anushtakin al-Dizbari, Thimal may have remained in Aleppo, while his elder brother Nasr managed to escape the Mirdasids' rout.
[8] During the engagement with the Byzantines, Thimal had remained in Aleppo with the bulk of the warriors of Banu Kilab to defend the city and its citadel should Nasr's cavalry be dispersed.
During the battle, Thimal fled with his Kilabi loyalists, leaving Nasr and a small core of supporters to be defeated and slain by al-Dizbari.
[16] Al-Dizbari's army ultimately besieged Aleppo and by June/July 1038, had captured it and expelled Muqallid and Khalifa, along with any Mirdasid loyalists left in the city.
[17] Thimal retained the Mesopotamian portion of Mirdasid emirate,[18] but al-Dizbari later captured Balis and Manbij from him, but was unable to take al-Rahba.
When her brother Shabib ibn Waththab died in 1039/40, she inherited the twin cities of al-Raqqa and al-Rafiqa and subsequently entrusted them with Thimal.
Thimal retreated to the Kilabi tribal encampments at Qinnasrin, but within a few days an opportunity arose to take Aleppo when the aḥdāth and the Fatimid troops entered into conflict over control of the city.
The aḥdāth consequently allowed Thimal entry on 22 February, forcing the Fatimid troops to barricade themselves in a palace adjacent to the citadel, which was held by al-Dizbari's former ghilmān (slave soldiers).
In the fall of 1048, Ibn Hamdan encamped his forces at Shildi, a village on the Quwayq River in Aleppo's vicinity for the dual purpose of remaining close to the city and having access to a water supply for his troops.
The Byzantine emperor unsuccessfully attempted to persuade al-Mustansir to halt the advance and consequently dispatched two armies to oversee developments in northern Syria.
To that end, he released all their war prisoners and entered into a mediation brokered by the Fatimid qāḍī (judge) of Tyre, Ali ibn Iyad.
[26] The latter persuaded al-Mustansir to accept a Mirdasid delegation headed by al-Sayyida al-Alawiyya and including Thimal's young son, Waththab, in late 1050.
Unlike his Mirdasid predecessors who relied on Aleppine Christians as their viziers, Thimal entrusted fiscal policy to a succession of viziers from his old powerbase al-Rahba, as well as Mosul: Abu'l Fadl Ibrahim al-Anbari, Abu Nasr Muhammad ibn Jahir and Hibat Allah ibn Muhammad al-Ra'bani al-Rahbi.
Among these was a severe drought and failed harvest in the emirate, a new state of war between the Fatimids represented by their expeditionary commander in Syria, Ibn Mulhim, and the Byzantines, and military pressure by al-Basasiri against Aleppo from the east.
[28] Thimal's inability to satisfy the financial demands of his tribesmen, the foundation of Mirdasid power, and his conflict with his brother Atiyya, who was based in Balis, caused dissensions against him within the Kilab.
[28] In the ensuing agreement, Thimal stepped down on 23 January 1058 and the Fatimids compensated him with the governorships or appendages of the coastal towns of Acre, Beirut, and Jubayl (Byblos).
Thimal's rule over the three coastal towns was evidently a tributary arrangement, as he did not exercise control over them and took up residence in Cairo with the blessing of al-Mustansir.
The latter mediated an end to the fighting whereby Mahmud surrendered Aleppo to Thimal on 23 April in return for significant payment in cash and grain and a yearly salary.
Against the latter, who had taken control of al-Rahba, Thimal dispatched his brother Atiyya with a Kilabi troop to restore Mirdasid possession of the strategic town in August 1061.
Zakkar theorizes that this was due to his lengthy stay in Cairo, where he may have come to realize the Fatimids were no longer capable of organizing a serious military campaign against Aleppo, and the Byzantines' preoccupation with Seljuk inroads into Anatolia and Byzantium's possible support for Mahmud in the 1060 fighting.
[34][35] On 28 November 1062, Thimal died "after leading several victorious operations against Byzantine encroachments in the mountains and plateaux situated between Aleppo and Antioch" (as referenced above), in the words of Bianquis.