Converted Persia: From Zoroastrian Fire Temple to Muslim Mosque

The Persian Empire is the name given to the vast empire centred in modern-day Iran that ruled for several centuries, from the sixth century BC (Achaemenid dynasty) to the twentieth century AD (Qajar dynasty). Under the Achaemenid dynasty, Zoroastrianism was the religion of the empire, and the chahar taq and the chahar bagh symbolised the Zoroastrian division of the universe into four elements: earth, water, wind, and fire. During the rule of the Sasanian Empire (224–651), the last Persian dynasty to rule in pre-Islamic Iran, architects used the four-ayvan style for facade composition: a large vaulted space closed on three sides and open on the fourth, facing a courtyard.

The Muslim conquest of Persia in 651 AD led to the decline of the Zoroastrian religion, but the fourfold form persisted as it also had a resonance with Islam, symbolising the four rivers of life described in the Qur’an. The Persian ayvan was adopted into Arabic as iwan, and the four-iwan style of mosque construction was used as an elaboration on the Prophet Muhammad’s early “courtyard mosque” or hypostyle (“under pillars”) design.

The hypostyle design allows for the construction of large spaces, such as temples or palaces, without the need for arches. You can see this construction style in the ruins of Persepolis, and in the Great Mosque of Kairouan in Tunisia, built in the 9th century and which follows the hypostyle design of the Prophet’s early mosque.