The Zaytuna mosque, or "olive tree" mosque, was initially built in 732 CE on the ruins of an old Roman basilica in the médina of Tunis, Tunisia. Though the original structure no longer exists, literary sources attribute its construction to builder Hassan ibn Nu'man. A century after its construction, the mosque was completely rebuilt by Aghlabid amir Abu Ibrahim Ahmed (reg. 856-863 CE) to emulate another of his large building projects the Great Mosque at Kairouan. The two mosques were reconstructed concurrently between 856 and 863 CE. In 864 renovations were funded by the Abbasid caliph Al--Musta'in. There are further similarities between the plan of the Zaytuna mosque and that of the Great Mosque at Córdoba (784-786, 961-976, 987 AD), a testament to the persisting influence that the Córdoba building had upon mosque design in Northern Africa.
An inscription at the base of the mihrab indicates that the master builder of the Zaytuna mosque's ninth-century reconstruction was Fathallah, a slave of the caliph. The mosque was further altered on several occasions after Ibrahim Ahmed's commission, including interventions in 991, the eleventh century, the thirteenth century, the mid-fifteenth century, the nineteenth century, and the late-twentieth century. Despite these substantial renovations to the ninth-century edifice, the Zaytuna mosque remains one of the most significant examples of Aghlabid and early Hafsid monumental architecture in northern Africa, as well as the oldest surviving mosque in the city of Tunis.
The mosque is located near the center of Tunis, in the middle of the four-kilometer-wide spit of land that separates the city's two major water bodies: Sebkhet el Sijoumi to the west and the Lake of Tunis to the east. The mosque is central to the larger Zaytuna complex, which also includes the Zaytuna University and adjacent souks. The arrangement of souks around the mosque was part of a traditional planning strategy that focused the development of urban economic centers near to significant religious institutions. This organization has persisted, as even today the entire western wall of the mosque complex is bounded by small cellular shops. The northern edge of the complex is bounded by Souk Attarine, which runs parallel to Rue de la Kasbah, a major thoroughfare through the médina of Tunis. Several other significant historic mosques are located within a one-kilometer radius of the Zaytuna mosque, including the Muradid mosques of Hammuda Pasha (1655 CE) and of Yusuf Dey (1616 CE).
In plan, the mosque measures approximately 75 meters along its east-west axis and between 64 and 78 meters along its north-south axis. The Zaytuna mosque occupies an area of roughly 5400 square meters, or 0.5 hectares. In all, there are twelve portals that provide access to the Zaytuna mosque. Two entrances to the mosque are located at the northern end of the eastern wall, where arched stone portals built in the fifteenth century open onto a generous sahn that measures 47 meters wide east-to-west and between 28 and 38 meters long north-to-south. Four additional portals allow entry to this central courtyard; two entrances are located along the northern wall, and two others are at the northern end of the western wall. Additional entrances create direct passages from the surrounding souks into the covered prayer hall. There is also a small door along the qibla wall, to the east of the mihrab, that allows the imam direct access to the prayer hall. This private entry is elegantly decorated, featuring an imported antique Roman lintel and carved marble columns.
The axis of the northern wall, which defines the edge of the sahn opposite the gallery bounding the prayer hall, is rotated 63 degrees east (clockwise) from the north-south meridian. The northern wall is rotated ten degrees farther toward the east than the qibla wall along the southern edge of the prayer hall. The axis defining the southern edge of the sahn is rotated four degrees to the west of the qibla wall, giving the prayer hall a slightly trapezoidal shape and an oblique column grid. The longitudinal axis of the central aisle of the mosque is rotated 33 degrees west (counter-clockwise) of the north-south meridian.
The prayer hall is the oldest portion of the surviving mosque, as it was constructed under Abu Ibrahim Ahmed in the ninth century. This hypostyle space is fifteen aisles wide and eight bays deep. While the seven aisles to each side of the hall measure 3.5 meters on center, the central aisle is slightly wider, spanning 5.3 meters at its center. The stone columns themselves measure approximately 50 centimeters in diameter. At the intersection of the central aisle and the transverse bay along the qibla wall is a cupola, above the space immediately before the mihrab niche. This ornate, four-meter-wide cupola was constructed in 991 AD during the Zirid period; it is notable for its delicate gadroons, or carved decorative mouldings, which possess a convex cross section. The location of the dome within the hall also highlights the T-shaped organization of the plan, a formal strategy common to North African mosques of the medieval period. The cupola over the mihrab niche was at the same time as that of the Great Mosque at Kairouan, yet the two domes differ in shape; the mihrab dome at Kairouan rises from an octagonal base and tambour, while the base of the fluted dome at Zaytuna is square with an octagonal tambour, and its decoration is more lavish in both material and form.
Another element of the Zaytuna mosque that was constructed contemporaneously with its counterpart at Kairouan is the minbar. The minbar of Zaytuna was less ornate than that of Kairouan, but attention was paid to restoring the original ninth-century Aghlabid structure during the renovations undertaken by the Hafsids in the mid-thirteenth century.
At the northern end of the central aisle is a second cupola, which marks the principal entrance to the prayer hall from the sahn. Larger and more ornate than the dome in front of the mihrab, this cupola was added during renovations in the tenth century, and its entire height is clearly visible from within the sahn. The tiled exterior of the dome features alternating courses of red brick and ochre stone. The detailing of the cupola is typical of Fatimid art; the density of small niches that cover the square base and octagonal tambour of the dome are characteristic of this architectural period.
The sahn is bordered on its northern and western sides by single-bay-deep arcades. These galleries were built after the ninth-century erection of the prayer hall, but before the construction of a raised, enclosed ablution facility accessible via the western gallery. This ablution chamber and the steps leading to it were erected in the mid-fifteenth century under Hafsid ruler 'Uthman b. Muhammad al-Mansur, Abu 'Amr (r. 1435-1488). The ablution facility is separated from the main volume of the mosque by adjacent souks, although a direct passage leads to the small fountain and courtyard from the interior of the central sahn. The two-bay-deep gallery that forms the eastern side of the sahn was also added during the mid-fifteenth century.
The first minaret, constructed by the Hafsids during the thirteenth century, collapsed in 1892 and was quickly rebuilt in 1894 in a Moroccan neo-Andalusian style. Surviving today, the nineteenth-century minaret reaches a height of forty-three meters. Its materiality and decorative scheme echo the detailing of the Almohad minaret of the nearby Kasbah mosque (1230 CE). Located at the northwest corner of the sahn and bordering the exterior walls of the mosque, the cubic shaft of the minaret features solid panels of ochre sandstone overlaid with carved limestone in a regular screen pattern.
Various stylistic periods are represented in the ornamentation of the Zaytuna mosque. Due to the renovation of the building under successive dynasties with differing architectural tastes, portions of the building have been restyled as discussed above, while others, such as the central portions of the prayer hall, have remained relatively untouched. The approximately 160 columns and capitals in the prayer hall were imported from the ruins of Carthage, and these ancient columns remain structural in the mosque today. Timber abacuses and stone imposts are used as support for the grid of horseshoe arches overhead. The marble columns and capitals that frame the galleries edging the sahn were imported from Italy during renovations undertaken by minister Khaznadar in the mid-nineteenth century. White marble was also used to surface the small arcaded courtyard which contains the ablution fountain.
The Zaytuna Mosque was renovated most recently in 1989 under the supervision of the Institut National d'Archéologie et d'Art, a governmental agency of Tunisia, with the support of then-president Zine al-Abidine Ben Ali (reg. 1987-2011). The focus of this restoration was the mihrab in the prayer hall, whose inner niche was resurfaced with local stone in a simple pattern. The historic mosque continues to host contemporary worship services, serving as the religious center of the Zaytuna University.
Ben Achour, Mohamed El Aziz. Jami' al-Zaytunah: al-ma'lam wa-rijaluh / Muhammad al-'Aziz bin Ashur. Tunis: Dar Saras lil-Nashr, 1991.
Blair, Sheila S. and Jonathan Bloom. The Art and Architecture of Islam: 1250-1800, 253-254. New Haven: Yale University Press, 1994.
Bosworth, Clifford Edmund. The New Islamic Dynasties, 31-32, 35-36, 45-47. New York: Columbia University Press, 1996.
Hillenbrand, Robert. Islamic Architecture: Form, function and meaning, 60, 74, 77, 81-82, 138, 244, 474. Edinburgh: Edinburgh University Press, 1994.
Maison tunisienne de l'edition. Mosquées de Tunisie, 80-81. Tunis: Maison tunisienne de l'edition, 1973.
Michell, George. The Architecture of the Islamic World, 221. London: Thames & Hudson, 1978.