Human beings are a riverine species. It has no gills, no fins, no webbed legs and yet its evolutionary path is inextricably linked to running waters. Rivers have stimulated the birth of cities and increasingly complex and structured societies, the expansion of trade and transport, technological and knowledge evolution, demographic growth and the improvement of living conditions. This book briefly retraces the thousand-year history of friendship between man and rivers, with chapters that deal with the different aspects of this indissoluble and asymmetrical relationship and in which historical reconstructions, scientific insights, amusing anecdotes and the author’s personal experiences alternate. There is no natural environment to which our species is more indebted for its progress. Even today it is estimated that almost the entire human population lives on the edge of rivers or a few kilometers from them. However, over time, the relationship between us and the river systems has deteriorated, eroded and then buried by our greedy restlessness, exponential population growth and the arrogance due to our ever-increasing technological and scientific capabilities. In this period of dramatic and rapid climate change, with the worsening of droughts and floods, with the deterioration of the quality and quantity of water, river management plays a role of absolute and primary importance. For this reason, retracing the history of our ancient relationship with rivers can be a good way to try to re-establish with them that pact of friendship that has brought us so far.