Why was the city of Kairouan founded in 670?

The city of Kairouan was founded in 670 by the Arab commander ‘Uqbah ibn Nāfi‘ to serve as a strategic garrison city and the first center of Arab administration in the Maghrib (northwest Africa).12

Its establishment was a key part of the Umayyad dynasty's systematic effort to consolidate authority and expand their influence in the region, particularly in the context of their ongoing confrontation with the Byzantine Empire. By creating a permanent military base, the Arabs were able to consolidate their control over Tripolitania and Ifrīqiyyah, providing a secure launching point for further territorial expansion and the subjugation of the region.231