Arab commander Uqba ibn Nafi founded Kairouan in 670 as a garrison city during the expansion of Muslim rule across North Africa. A congregational mosque established near its center became the ancestor of the Great Mosque, also known as the Mosque of Uqba. The earliest structures were rebuilt several times as the city faced political change and warfare. Kairouan grew from military foundation into a capital, market, pilgrimage center, and place of scholarship connecting Ifriqiya with the wider Mediterranean, Sahara, Egypt, and Islamic world.

Most of the mosque's present plan and monumental character date to Aghlabid rebuilding in the ninth century, especially under Ziyadat Allah I and later rulers. A vast arcaded courtyard leads to a hypostyle prayer hall whose reused Roman and Byzantine columns and capitals came from many earlier sites. The square three-tiered minaret developed through successive campaigns and became an influential model. Domes, carved wood, marble panels, ceramic tiles, and the celebrated minbar expressed both local craftsmanship and long-distance artistic exchange while the complex anchored law, theology, teaching, and urban identity.

Kairouan lost political primacy as capitals moved, and Hilalian incursions in the eleventh century disrupted the region, but the mosque retained exceptional religious authority. Hafsid, Ottoman, and Husainid patrons repaired roofs, gates, arcades, decoration, water systems, and precinct buildings. Scholars and popular devotion strengthened the city's status as a holy place in the Maghreb. French colonial administration classified and restored monuments, sometimes replacing materials or emphasizing an idealized early Islamic appearance. After Tunisian independence, national religious and heritage authorities continued conservation within a living medina.

The mosque preserves extensive ninth-century masonry, plan, minaret fabric, columns, mihrab decoration, and early woodwork, but no part has remained free from maintenance. Roof timbers and tiles require renewal; stone and plaster have been repointed or replaced; ancient columns were already reused when installed; and later gates and repairs belong to the monument's history. Courtyard paving, lighting, barriers, carpets, sound systems, and visitor controls include modern work. The complex is not a reconstruction, yet describing it as entirely original to 670 ignores the repeated rebuilding after Uqba's foundation.

Tunisia's religious institutions administer worship while national and local heritage bodies protect the mosque within the UNESCO-listed Medina of Kairouan. Access for non-Muslim visitors, prayer-hall entry, dress, and schedules depend on current religious and conservation rules. Interpretation should distinguish the founding tradition from the largely Aghlabid standing complex and recognize reused classical material without treating Islamic builders as merely borrowing. The Great Mosque's authenticity rests on enduring sacred use, early medieval fabric, and legible additions and repairs across centuries, not on an impossible single-date purity.