Studying mine-drainage works of a medieval principality living through times of war, social turmoil, and land reclamation, this book examines the relation between political power and mineral wealth. It argues that mine-drainage works in Monte Calisio, Trento emerged when violent economic warfare within the upper class created profit horizons that capital seized in the subsoil of the principality. From that moment forward, war against hydrogeological conditions justified the existence of private mining capital in the principality. This book shows that hegemonic powers striving to manage mineral wealth failed to monopolize the forces of economic change that sustained their ground as these forces shifted profit relations. Increased mining rents and profits placed a heavy burden on Prince Bishop Wanga, leading to explosive contradictions concealed in the rise of private mine-drainage works. The book offers an illuminating interpretation of the role mining played in the rise and fall of European resource hegemonies.