Ribāt of Sousse

The Sousse ribāt, which stands at the far eastern end of the medina, near the Great Mosque, is part of a broken chain of defence that according to Ibn Khaldūn extended all along the southern shore of the Mediterranean from Ceuta to Alexandria. Ifiriqiyan ribāts seem to take their inspiration from two sources: their Abbasid equivalents[1], which were established to defend the northern borders against the Byzantine threat and the eastern borders against the danger represented by the Turkish populations of Central Asia; and the Umayyad buildings that used to be known collectively as “desert castles”[2].

The building has a square plan and seems to be modelled on the Monastir ribāt, which was imitated throughout the Muslim West. It is made up of a central courtyard surrounded by rooms and an upper floor that houses a prayer hall. With its ramparts flanked by semi-cylindrical towers, its general plan recalls that of Abbasid palaces[3] . The façade crowned with merlons is occupied on the south-east by a cylindrical look-out tower set on a square base and surmounted by a lantern-turret covered with a small ceramic dome. Added by Ziyādat Allāh I in 821, the tower served as a minaret for the adjacent mosque. This form spread throughout the Maghreb from the late eighth century on, particularly in Ifriqiya[4], where shortly thereafter, however, square-base minarets like that of the Great Mosque of Kairouan, modelled after the Great Mosque of Damascus (706), became the preferred style and were later adopted all over the Muslim West[5].

The ribāt is approached through a rectangular entry porch whose semicircular arch rests on columns topped with Corinthian capitals. Over the porch is a room surmounted by a cupola supported by squinches. The room contains a defence system consisting of murder-holes, machicolations and the groove of a portcullis. This system is the outcome of continuous development introduced by Muslims before the system of bent entrances was adopted. Machicolations separated by stone arches are an Islamic invention which was later to inspire the Crusaders as a means of defending some of their fortified castles in the Near East.

This type of cupola would later appear in the Great Mosque of Kairouan and spread into Sicily, the Maghreb and Spain, the south of France and Italy. But here, the absence of a drum heralds more particularly the forms adopted by the Sahelian school of architecture[6], which would spread to Sicily[7], a region that came under Muslim domination in the ninth and tenth centuries.

The visitor steps across the porch into an entrance vestibule that gives out onto a courtyard surrounded by porticos. Against the southern portico are two staircases leading to the upper storey, which is occupied by cells built to accommodate the ghāzī (invaders) and by a prayer hall. The prayer hall is divided into two bays and eleven naves perpendicular to the qibla wall, delimited by semicircular and surbased arches resting on pillars. This layout is altogether comparable to that of the neighbouring Great Mosque, the earliest one to have arches in two directions[8]. The semicircular mihrāb has a stilted semicircular arch supported by columns.

The southern wall, which has pillars built against it that receive the thrust of the arches running north to south, is pierced with six openings that seem to be loop-holes.

As one by one the countries around the Mediterranean fell under Muslim domination, ribāts gradually lost their military function and were often re-used for other purposes, in particular for teaching.

[2] Mshatta Palace, Jordan, 743-744. http://archnet.org/library/ime.jsp?location_id=9084&image_id=150424

[3] Palace of Ukhaydir, Iraq, Koufa, 764-778.

[4] Ribāt of Monastir (AH179/AD 796), Great Mosque of al-‘Abbasiyya (Palestine), first capital of the Aghlabids in AH 185/AD 801

[5] Mosque of al-Qarawiyyīn, Fez, Morocco, ninth–tenth centuries.

[6] Cupola of the Great Mosque of Sousse (851), cupola of the Great Mosque of Sfax

[7] Palatine Chapel, Palerma, Sicily, 1132-1143. http://archnet.org/library/images/one-image.jsp?location_id=9345&image_id=50781                                                                                   

[8] The cistern of Ramla (Jordan, 789) offers the earliest preserved example in Islamic architecture of arcatures running in both directions. This principle was to become typical of the architecture of North African mosques.