By the later 5th c. A.D., Constantinople was the greatest urban centre in the Mediterranean world. This paper considers three associated elements of the infrastructure of the city, each of which applied aspects of ancient technology: a first theme will consider the urban terraces which have only been studied in detail for the area of the Great Palace, but which represent a massive investment in the transformation of the built topography of the city; a second theme will examine the new Theodosian fortifications and suggest that these reflect a new level of innovation more often associated with the religious and civic architecture of the city; the third theme will briefly review recent research on the water supply and will identify major areas of continuity and innovation into the Middle Byzantine period.
