Some time after the founding of Baghdad in 145/762, Abū Ǧaʿfar al-Manṣūr, the second caliph of the Abbasid dynasty (r. 754-775), granted an audience to a Byzantine ambassador from the emperor’s court at Constantinople. When the caliph asked for the visitor’s opinion of the nascent capital, the latter did not hesitate to point out its most serious flaw, namely that the presence of the markets within Baghdad’s administrative core – the walled “Round City” – posed a serious threat to security. Though initially hesitant to act on the Greek’s criticism, al-Manṣūr eventually responded resolutely by ordering that the markets be transferred outside the walls to al-Karḫ, a district to the south which predated the caliph’s city.
So, in any case, we are told. This account appears in at least four versions, each taking up about half of a printed page or less. The first appears in the chronicle of al-Ṭabarī (d. 310/923) in a collection of reports concerning the planning, building, funding and org...


