The Zirids emerged from the Sanhāja after Zīrī ibn Manād and his followers demonstrated their loyalty during the struggle against Abū Yazīd’s revolt. The Fatimid caliph rewarded Zīrī with command over the Sanhāja and their territory. Later, Bulukkīn ibn Zīrī was appointed lieutenant over the western part of the empire when al-Muʿizz departed for Egypt in 359/972.

The Zirids represented a major political change in the Maghrib. Earlier ruling houses had originated in the East, whereas the Zirids were the first reigning dynasty of Berber origin. Their rise inaugurated a period in which political authority in the region was increasingly held by Berber dynasties, including the Almoravids, Almohads, Zayyanids, Marinids, and Hafsids.

Under Bulukkīn, al-Mansūr, and Bādīs, relations with Cairo remained formally correct. Tribute was paid and gifts were sent, but the Zirid emirs sought greater practical independence. Fatimid attempts to restrain them included political representatives and the incitement of a Kutāma revolt against al-Mansūr in 375/986. The suppression of that revolt strengthened Zirid authority and weakened the Kutāma as a political and military force.

The Zirids fought the Zanata and their Umayyad allies in the western Maghrib, while also confronting revolts within their own territories. Hammad ibn Bulukkīn founded the fortress-capital of the Banū Hammad in 398/1007–8 and proclaimed independence in 405/1015. The Sanhāja polity consequently divided between the Zirids in Ifrikiya and the Hammadids in the central Maghrib.

Al-Muʿizz ibn Bādīs broke with the Fatimid suzerain in 439/1047 and recognized the Abbasid caliph, abandoning the Ismaili creed for Sunni Islam. The Fatimids responded by directing the Banū Hilāl and Banū Sulaym toward Ifrikiya. After defeat at Haydarān in 443/1051–2, the Zirid ruler abandoned Kayrawān in 449/1057 and sought refuge in al-Mahdiyya, while the former capital was sacked.