rénovation complète en 221 H. / 836 ; salle de prière agrandie de trois travées et portiques ajoutés en 875.
This mosque, the oldest and most prestigious sanctuary in the Muslim West, is built over a seventh-century oratory renovated in 703. Its present shape reflects the work of Ziyadat Allah I, who ordered the reconstruction of the edifice in 836.
The structure is built in dressed stone cut like brick. This choice probably points to the influence of the architectural traditions of the Muslim East, where brick was the chief construction material. The mosque looks like a fortress pierced with eight doors and studded with towers and bastions. They are actually porches and buttresses added during the Hafsid and Ottoman periods.
The central courtyard is paved with marble slabs and framed with porticos formed of round horseshoe arches resting on ancient columns, making this mosque the largest museum of Roman and Byzantine capitals ever gathered in an Islamic monument. This collection embodies the spirit of tolerance that has always characterised this civilisation.
The double-arched porticos, which are reminiscent of the Abbasid model, rest on double columns. The middle of the portico on the prayer hall side, in line with the mihrāb, is enhanced by a high, wide arch flanked by two narrower ones, creating a tripartite arrangement similar to Roman triumphal arches and the Great Mosque of Damascus (705–715). The nave at the back of this portico, also in line with the mihrāb, is enhanced by a cupola built under the reign of Ibrahim II (875–902). The northern portico is occupied by the minaret.
The hypostyle prayer hall built in the Umayyad tradition is composed of seventeen naves perpendicular to the qibla wall and eight bays. A wider bay along the qibla wall meets the wide central nave emphasised by double columns, forming a T. This T shape was to feature in Fatimid architecture from the tenth century onward. The juncture of the two elements forms a square area in front of the mihrā, with a ribbed cupola on squinches overhanging it. The forms and motifs gracing the cupola (shells, multifoil arches, rosettes) draw their inspiration from the Umayyad repertoire while at the same time conveying certain Abbasid designs such as squares laid point to point. The prayer hall also has a maqsura and a minbar.
The prayer hall ceiling is made of carved and painted wood. Renovated several times, it presents motifs typical of each period.
By virtue of its diverse forms and rich ornamental repertoire, this monument embodies the Kairouan school of architecture, which prevailed exclusively in a large part of the Maghreb for four centuries.
The plan, which without a doubt was inspired by the plans of the al-Aqsa Mosque in Jerusalem (709–715) and the Damascus Mosque (706), displays a noteworthy development – the T-shaped plan, which came into being as a result of the emphasis on the bay of the mihrāb. It served as an example for most Ifriqiyan mosques up until the Ottoman era and spread into central Maghreb, Morocco, Sicily, Spain, Libya and Fatimid Egypt.
The outstanding feature of the cupola on squinches in front of the mihrāb is its middle area, which is made up of small columns and horseshoe arches, and an elaborate shell decoration that points to great technical mastery. This suggests that the region had a long tradition of building cupolas. We cannot dismiss the idea that the construction of cupolas is a Byzantine legacy, yet we cannot rule out the possibility of the influence of Mesopotamian cupolas on squinches, probably inherited from Sassanid architecture, which spread widely in the Islamic world in the Abbasid era. This type of cupola spread into Ifriqiya and also appeared in Sicily, Morocco and Egypt.
 Prayer hall, cupola, minaret, outer walls.
 Note that the size of the columns is harmonised by the use of bases and imposts of different heights.
 See the Abu Dūlaf Mosque in Sāmarra, Iraq, 847–861.
 The use of double columns can also be seen in the Great Mosque of Cordoba, Spain, 786–988.
 See the Great Mosque of Damascus, Syria, 706, where the central nave is already wider.
 There are naves perpendicular to the qibla in the Great Mosque of Cordoba, Spain, 786–988.
 Great Mosque of Mahdiyya, Tunisia, 912. Al-Azhar Mosque, 970–972, Egypt, Cairo, which features the same enhancement of the nave in line with the mihrāb.
 The oldest part (ninth c.), decorated with foliated scrolls and fleurons, is completed by a Zirid part (early eleventh c.) with inscriptions in flowery Kufic. Restoration work was carried out under the Hafsids (late thirteenth c.) and then at the time of Murad I in 1618.
 Qala'at Bani Hammad (Algeria, eleventh c.), Mosque of Constantine (Algeria, 1136), Great Mosque of Tlemcen (Algeria, 1136).
 Mosque al Qarawiyin in Fez (ninth–tenth c.), Tinmel Mosque (twelfth c.), Mosque of Hassan in Rabat (twelfth c.).
 Al-Azhar Mosque (969–973), al-Hâkim Mosque (990 and 1013).
 The al-Sulaybiya cupola in Samarra (862) is one of the oldest examples we have of this type of cupola.
 Cupolas of the mihrāb and bahou of the Zitouna Mosque in Tunis (856–864), cupola of the mihrāb of the Great Mosque of Sousse (ninth c.).
 La Cubola in Palermo (1180).
 Al-Hākim Mosque (990 and 1013)and al-Juyushi Mosque (1085) in Cairo.
Creswell, K.A.C., Early Muslim Architecture, t.II, New York, 1979, Hacker Art Books, p. 208-226, 308-320.
Lézine, A., Architecture de l’Ifriqiya, Recherches sur les monuments aghlabides, Paris, 1966, Klincksieck, p. 11-52.
Maoudoud, K., Kairouan, Tunis, 1991, ANEP, p. 20-31.
Marçais, G., Manuel d’art musulman, 2 vol., Paris, 1926-1927, Picard, p. 15-32.
Golvin, L., Essai sur l’architecture religieuse musulmane, Paris, 1970, Klinksieck, p. 133-149.
Mozzati, L., L'art de l'Islam, Paris, 2003, Mengès.
Stierlin, H., L'art de l'Islam en méditerranée d'Istanbul à Cordoue, Paris, 2005, Gründ.