The Founding of the Round City of Baghdad

In 145 AH (762 CE) the second Abbasid caliph, Abu Ja'far al-Mansur, founded a new capital on the west bank of the Tigris and named it Madinat al-Salam, the City of Peace, the city the world would know as Baghdad. The Abbasids, victors of the revolution that had toppled the Umayyads, would not rule from Umayyad Damascus; al-Mansur sought a site at the heart of Iraq, between the Tigris and the Euphrates, where canals, river traffic, and the great roads of the empire met, with a climate and a food-supply to sustain a capital. He chose a plan unique among the cities of Islam: the Round City (al-Mudawwara), laid out as a perfect circle with a double ring of fired-brick walls and a deep moat, pierced by four equidistant gates set to the cardinal directions and each named for the land it faced and the road that ran to it, the gates of Kufa, Basra, Syria (al-Sham), and Khurasan. At the centre, in a great open court, stood the caliph's palace, the Golden Gate (Bab al-Dhahab) crowned by a green dome, and beside it the congregational mosque; between the centre and the walls lay the rings of streets and quarters. The sources describe al-Mansur having the plan traced on the ground in lines of ash and walking the circuit before the work began, and his astrologers, among them the astronomer Mashallah, electing an auspicious date for the foundation, a sign of the Persian and scientific culture the Abbasid court was drawing in. Within a generation Baghdad would become the largest city of the world outside China and the centre of a brilliant age of learning. The foundation is preserved above all in al-Khatib al-Baghdadi's history of the city and in al-Tabari, with the later geographers Yaqut and al-Muqaddasi. Nothing of the Round City survives above ground; its plan is known only from these descriptions. Workers build a curved brick enclosure beside a river. This compressed construction scene suggests the famous round plan but cannot show the capital at its historical scale.