The origins of Islam and the first Swahili mosques in East Africa are evidenced by the results of Mark Horton’s excavations in Shanga (Lamu, Kenya) and the author’s own research in Gedi (Kenya), in Songo Mnara and Sanjé ya Kati (Kilwa, Tanzania) (Horton 1996; Pradines 2009). Swahili mosques have a rectangular prayer hall flanked by narrow lateral wings usually comprising one-third of the width of the central hall. These mosques do not have a minaret and are bordered by a small courtyard where ablutions are practiced. Some mosques comprise a central row of pillars, facing the mihrab. The niche of the mihrab is in the form of a square, not integrated into the wall but jutting outside the mosque. The plans of Swahili mosques have a number of similarities with their counterparts in South Arabia, notably on the shores of the Hadramaut and Oman. Thus, in the fifteenth century, the mihrab of the Great Mosque of Gedi was decorated with 13 blue and white porcelain vessels inserted into the tympanum and the lower side of the apse. This use of ceramics as a decorative element of the qibla or the mihrab, is also evident in Oman in the Shawâdhnâ of Nizwa mosque, dated 1530 and decorated with an inlay of cut blue and white porcelain.
According to oral traditions in many Swahili cities, the first stone mosques were associated with the Shirazis. The so-called Shirazi mosques, of eleventh- to twelfth-century date, seem to have had consistent proportions; thus in Gedi, the first mosque was c. 10 by 7 m. In Tanzania, the great mosque of Kilwa was erected between 1131 and 1170 (Freeman-Grenville 1962: 34-38). Its initial rectangular plan does not differ from the model previously described, measuring 11.8 by 7.8 m. Also in the Bay of Kilwa, the Island of Sanjé ya Kati houses a large mosque founded in the second half of the eleventh century; with its lateral wings, the mosque measures 10.21 by 9.46 m. The Shanga mosque, the final construction phase of which dated from the fourteenth century, may have been founded earlier. What is certain is that a mosque was constructed in Shanga between 1015 and 1035, decorated with blocks of sea coral. The eleventh-century building forms a rectangle measuring 11.22 by 7.21 m. During archaeological excavations at Tumbatu (Island of Zanzibar), Catherine Clark and Mark Horton unearthed the foundations of a Friday mosque from the twelfth century.
It was during the eleventh century that Swahili builders adopted coral to construct their mosques. This material was used for walls until the twelfth century. Its extraction was not easy, and it was thus used for fine sculptures around the mihrab. The sea coral was replaced by limestone coral from the thirteenth century. This fossil rock forms the geological substratum of the entire eastern coast. The blocks were taken from open-air quarries, not far from the construction site. The first buildings were assembled using coral stones cut in rectangular blocks and set in lime mortar. At the end of the fourteenth century, stone mosques became widespread and eventually reached large dimensions, such as that in Gedi, 26 m long. From this period, the walls of the buildings were erected using a formwork of irregular stones embedded in lime mortar.
The Islamization of the African coasts was connected with Shi‘ite communities from the Persian Gulf, and the oldest-known Swahili mihrab is indicative of these transoceanic influences. The mihrab of Kizimkazi on the island of Zanzibar is decorated with a passage from the Qur’an, and bears the date 1107 (Flury 1922). The niche is decorated with floral kufic inscriptions along the capitals and within the apse. The islands of Bahrain and Zanzibar share this particular type of mihrab (Kervran 1990: 31, 48). In Bahrain, the Suq al-Khamis Mosque has a floral kufic inscription with a shi‘a inscription mentioning the Twelver imams.
References on Swahili Mosques and religious architecture
2011 – « Commerce maritime et islamisation dans l’océan Indien : les premières mosquées swahilies (XIe-XIIIe siècles) », dans La mer et le sacré dans le monde musulman, Revue des Mondes Musulmans et de la Méditerranée n°130, Presses universitaires de Provence, p. 131-149.
2003 – Le mihrab swahili : Evolution d’une architecture islamique en Afrique subsaharienne, Annales Islamologiques 37, IFAO, Le Caire, p. 355-381.
2000 – Rituels funéraires swahili : les sépultures islamiques du site de Gedi (Kenya), Les Recherches sur le Monde Arabe en France, 1er Colloque des Jeunes Arabisants, CEMAA-AMAM, Université de Toulouse, p. 167-193.