Confirmation of a predating of the First Abbasid Masjid-i Jumʿa in Isfahan. The nahr Farsān as the mādī Fadan

The first Abbasid Masjid-i Jumʿa in Isfahan, underneath the present-day building, was brought to light by the Italian Archaeological Mission in the 1970s. An in-depth study of the unedited archaeological data obtained from the excavations has allowed the author to equate the mosque with the building described by some historical sources as having been erected close to the ancient nahr (canal) Farsān by the Abbasid governor Ayyūb ibn Ziyād in 767. This paper aims to present some new observations that support this hypothesis. In particular, extending the research to incorporate the study of the water canalization of Isfahan, mostly dated to the Safavid period, suggests the possibility that the mādī Fadan – an old branch of a canal running very close to the present-day mosque – could be identified with the nahr Farsān, thus confirming the identification of the excavated mosque with the 767 building.