Mu'izz al-Dawla Thimal

Abu Ulwan Thimal ibn Salih ibn Mirdas (Arabic: أبو علوان ثمال بن صالح بن مرداس, romanized: Abū ʿUlwān Thimāl ibn Ṣāliẖ ibn Mirdās; died 1062), also known by his laqab (honorific epithet) Mu'izz al-Dawla (Arabic: معز الدولة, romanized: Muʿizz al-Dawla), was the Mirdasid emir of Aleppo jointly with his elder brother Shibl al-Dawla Nasr in 1029–1030 and then solely in 1042–1057 and 1061–1062.

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. When Nasr was slain by the Fatimid army of Anushtakin al-Dizbari in 1038, Thimal took control of Aleppo but quickly departed to avoid a Fatimid assault. He once again reverted to his Jaziran domains, which were reduced by Anushtakin's captures of Manbij and Balis. Nevertheless, he gained the Numayrid city of Raqqa after marrying Nasr's widow, the Numayrid princess al-Sayyida al-Alawiyya.

After Anushtakin died in 1042, Thimal assumed control in Aleppo with Fatimid support. Nevertheless, he allied with the Byzantines, becoming a vassal of their empire, to the opposition of the Fatimids. After three abortive Fatimid campaigns against him, Thimal reconciled with the Fatimid caliph al-Mustansir in 1050, while maintaining his tribute to Byzantium. The resulting peace brought stability to the Mirdasid realm for the next seven years, during which Aleppo grew and prospered.

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. When the Fatimids' governor of Aleppo was ousted by Thimal's nephew, Mahmud ibn Nasr, in 1060, Thimal reasserted control over the city. He spent much of his short second reign campaigning successfully against the Byzantines.