bEnglish Summary b In the Middle Ages, new forms of water use, in particular the construction of mills and associated hydraulic engineering measures, led to major changes in landscape and environment such as settlement structures and social structures. The volume follows these changes. The grave changes in the use of waterways that took place in the aftermath of the High Middle Ages land development are manifested in different ways in written records, archaeological finds and findings as well as in geographical names. Most of the volume's contributions are devoted to water mills. It also highlights the role of rivers as transport routes. Geographically, the focus is primarily on the river basins of Oder and Vistula, but also on those of the Elbe, Rhine, Main and Danube and on Transylvania. bGerman Description b Im Mittelalter kam es durch neue Formen der Nutzung der Gewasser, insbesondere die Errichtung von Muhlen und damit verbundene wasserbauliche Maanahmen, zu groaen Veranderungen f