In a chapter dealing with the vicissitudes of urban civilization over more than two millennia, comprehensive coverage is out of the question. Instead, some of the themes of this series of three books are examined through the lens of a period that raises problems of historical interpretation in an acute form. The main difficulty is the fragmentary and uneven nature of the data. Written evidence is available from very soon after the emergence of the first cities, but its survival depends on the materials used and the conditions under which they happen to have been kept. The preservation of artefacts also depends on materials and conditions: biodegradable materials such as wood, textiles and leather survive only in special environments such as waterlogged peatbogs, arid Egyptian tombs and the permafrost of the Altai Mountains; whereas building stones, pottery and glass are eminently durable. But many durable materials, especially precious stones and metals, have been plundered by history’s asset-strippers, from ancient tomb-robbers to modern colonialists, and partly for these reasons the recovery of entire settlements is rare. Another reason is that many important sites have been continuously occupied and developed, and as a result the early history of many of the locations evidently most conducive to urbanization is irretrievably buried.