Writing with authority and brio, Giulio Boccaletti-honorary research associate at the Smith School of Enterprise and the Environment, University of Oxford-shrewdly combines environmental and social history to examine the profound influence of water on human civilisation. Beginning with the earliest sedentary farmers on the banks of the Nile, the Tigris, and the Euphrates Rivers, Boccaletti describes how these societies were made possible by sea-level changes from the last glacial melt and incisively investigates how agricultural innovations like irrigation and multiple cropping led to a population explosion and labour specialization. We see with clarity how irrigation informed social structure (inventions such as the calendar sprang from agricultural necessity); how in ancient Greece, the communal ownership of wells laid the groundwork for democracy; how the Greek and Roman experiences with water security resulted in systems of taxation; and how the modern world as we know it began with a legal framework for the development of water infrastructure. Monumental in scope and deeply insightful, Water: A Biography enriches our understanding of our relationship to-and fundamental reliance on-the most essential substance on earth.