Central Maghreb from Tahert to Tlemcen, then Sédrata and M’zab.

The egalitarian schism represented by Kharijism was for the people of Maghreb the political arm that allowed them to establish their opposition to Sunni orthodoxy and Arab despotism. The occupying forces showed a genuine contempt for new converts, obliging them to pay taxes normally only payable by infidels (kharadj and djizia, land and poll taxes) for example.
In AH 143 / AD 761, 'Abd al-Rahman Ibn Rustam (the founder of the Rustamid dynasty) established the Kharijite imamate of Tahert near to modern-day Tiaret, to the southwest of Algiers. At the same time, Abu Qurra was creating a Kharijite kingdom in the area around Tlemcen. By 154 / 771, these two kingdoms held Central Maghreb and Ifriqiya. Shortly afterwards, an Alid named Idris established another dissident emirate, first in Fez and then Tlemcen.
The Abbasid dynasty took 15 years to quell the revolt, without ever managing to regain control of the whole of Maghreb. The kingdom of Tahert grew throughout the 3rd / 9th century following the principles of the Ibadite doctrine of Kharijism (egalitarian puritanism, theocratic government and religious zeal), which did not prevent the birth of a refined civilisation enriched by the numerous new arrivals from the East, who had been attracted by the religious, intellectual and commercial atmosphere of the Rustamid capital. The Ibadites were driven out in 296 / 909 with the succession of a new dynasty in Maghreb: the Fatimids. They found refuge in the Sahara, and the Rustamid's second capital at Sédrata (Isedraten), near to modern-day Ouargla, produced a wealth of decorative styles inspired by a range of different artistic influences.
Again persecuted, in 433 / 1042 the Ibadites established five towns at the bottom of the M'zab valley 600 kilometres south of Algiers, where the descendants of the Mozabites still live today, perpetuating their doctrine and using all of their ingenuity to survive in a hostile environment.