The Great Mosque of Shushtar is located in the historic section of the city, adjacent to the suqs, but once sat in the midst of markets. According to textual sources, its construction was initiated in the late ninth century during the reign of the Abbasid caliph al-Mu'tazz Bi'llah (r. 866-869/252-255 AH). It was subsequently added to by other Abbasid caliphs but only completed during the reign of al-Mustarshid Bi'llah (r. 1118-1135/512-529 AH). Since that time, the mosque has been repaired numerous times, and today's building preserves little hint of the Abbasid design. 

The mosque is a semi-rectangular complex comprising a hypostyle prayer hall and simple courtyard. The prayer hall was originally thirteen bays wide and six bays deep, supported by five rows of twelve columns. The four westernmost aisles have been shortened progressively by one, two, and three bays, so that the building's western corner is cut away. The exterior of the prayer hall is noteworthy for its rows of buttresses, which project from the building on all sides, including the facade facing the courtyard. On the interior, the bays are vaulted and supported by large, stone pillars with angled corners to form octagons. These pillars and the vaults date to a renovation of the building that took place in 1677/1087 AH.

The mosque's cylindrical minaret dates to the late thirteenth or early fourteenth/ late seventh or early eighth century AH. It is decorated with square kufic calligraphy in glazed turquoise brick.

Sources:

Finster, Barbara. Frühe Iranische Moscheen, 252-253. Berlin: D. Reimer, 1994. 

Ḥājjī-Qāsimī, Kāmbīz, ed. Ganjnāmah-i farhang-i ās̲ār-i miʻmārī-i Islāmī-i Īrān. Vol. 8, 16-21 [English text: 172-177]. Tehran: Dānishgāh-i Shahīd Bihishtī, 2004.

Matheson, Sylvia A. Persia: An Archaeological Guide. Park Ridge, NJ: Noyes Press, 1973.

Record updates:

•    January 2019 (AKDC Staff): updated description to reflect information from additional sources on dating; updated references.