Modern water-supply systems — hidden beneath the ground, constructed, expanded, adapted and repaired intermittently by multiple groups of people — are often messy and difficult to comprehend. The ancient water-supply system we consider here is no different — and perhaps even more complex as it was developed over 1200 years and then had a modern city built on top. Despite this, we are beginning to understand how one of the Roman world's most important cities provided its population with water.

The remains of water infrastructure in Constantinople attest to a complex system of water-management and distribution, one that developed from the colony of Byzantium, through the growth and eventual decline of the new capital of the Roman empire, until conquest by the Ottomans. Aqueducts — the system of channels, bridges and tunnels designed to carry water through the landscape — were the focus of infrastructure investment in earlier periods, but cisterns for the storage and distribution of water were constructed throughout the time of Byzantine Constantinople.