Managing access to clean water and large quantities of grain and other foodstuffs was essential for the development of an exceedingly large city such as Baghdad under the Abbasids. With half a million or more inhabitants this was not an easy task. Still we do not fully understand how this was achieved. Existing historical approaches still often frame the institutional arrangements of Middle Eastern cities in relation to the premodern European city and emphasize the institutional weakness of the former. Yet how, then, did these cities support their numerous populations under challenging circumstances? In this combined presentation Hugh Kennedy will discuss the availability of river transport while Maaike van Berkel investigates the multiple water systems that functioned in Abbasid Baghdad and the source(s) of their sustainability.