In the Western Iranian highland town of Golpayegan, the lofty brick dome towering above the roofs announces the Friday Mosque to the visitor approaching through the surrounding river oasis, which lies embedded in the mountain ranges of the Zagros. Upon entering the mosque, the building presents itself as a rather unassuming courtyard complex - except for the dome chamber. This room stands out against the rest of the mosque because of its architectural decoration, with brick patterns and stucco ornament. On this building, two characteristic elements of Islamic art can be observed at a very early stage: Muqarnas in regular rows of cells adorning corner squinches, and inscriptions in square Kufic.
The Friday Mosque of Golpayegan is a building of high architectural standards, which experienced many turns in its history through the past nine centuries. This alone would justify a thorough examination. Besides, the exploration of the mosque can contribute to clarify overarching questions concerning the history of mosque architecture in Iran.
Among the mosques with a Saljuq dome chamber, the Friday Mosque of Golpayegan holds a relatively early position. The date of 508/1114-15, inscribed ...see more on the lower frame of the mihrab, was discovered twenty years ago. It puts the dome about twenty years after the first impressive dome chambers in the Friday Mosque of Isfahan, contemporary with the dome chamber in the Friday Mosque of Qazvin, and well before the dome chambers of Barsiyan, Borujerd, and Ardestan, to name the most important examples.
Concerning its position within the structure of the Friday Mosque, the dome chamber of Golpayegan appears clearly separated from the adjacent parts. The vaulted halls surrounding the courtyard, together with the two extant entrance bays, can be dated to the early Qajar period. Likewise, two walls perpendicular to the front of the dome chamber just like lateral walls of an iwan, belong to this building phase, while the hall on the opposite side of the courtyard has been replaced by a modern concrete construction. There is a clear joint between the Saljuq and the Qajar parts of the building.
More important for the older phases of the mosque were elements of stucco decoration, which can partly be ascribed to the Saljuq building phase of the dome chamber. Typical for the period, they contain grid patterns, tendrils and leaves. Stucco plugs from the joints between the bricks were also characteristic. Some elements, however, seem to date from a pre-Saljuq construction. Among them, a small feathered half palmette is similar to elements of the Buyid phase at Ardestan. Clear evidence of such a pre-Saljuq mosque was unearthed in the dome chamber: foundations of a pillar, which was obviously razed to pave the way for the construction of 508/1114-15. While the foundations have a square plan, the pillars themselves seem to have been cylindrical. This is indicated by a considerable number of wedge-shaped bricks which are built into the lower layers of the Saljuq dome chamber, or were used to pave the floor, obviously in secondary use. It can be concluded that the pre-Saljuq Friday Mosque of Golpayegan followed the type of the hypostyle hall. According to the style of stucco fragments, this building can probably be dated to the 4th/10th century. Traces of an even earlier building phase can be seen in the remnants of mud brick and adobe which were visible in the lower layers of the soundings.