Al-Mansur succeeded his father Buluggin ibn Ziri (r. 972–984) in Ifriqiya. Despite further campaigns by the Zirids against the Berber tribes of Morocco, he was forced to abandon the attempt at a permanent conquest of Fez and Sijilmasa. Still, he was able to consolidate Zirid rule in the central Maghreb when he defeated the Kutama Berbers in 988, and when his brother Hammad ibn Buluggin, as governor of Algeria, drove the Zanata Berbers into Morocco. The vassal relationship to the Fatimids became increasingly loose under al-Mansur, not least because their focus of attention was on the overthrow of the Abbasids in Iraq.
He was succeeded by Badis ibn al-Mansur (996–1016).