Medieval Latin Christendom had an environmental history. How people engaged with nature had a bearing on their lives and their fate. This book means to show students, practitioners, and consumers of medieval studies and environmental studies this simple truth. The interaction of European nature and medieval culture writ large mattered then and says something of moment to those who would now listen. All three central themes of environmental history – environmental influences on human activity, human attitudes towards the natural world, and human impacts on the non-human – pertain to stories and outcomes interlaced through a millennium of Europe’s past. Those narratives deal with problems of resource use, ecological balance, pollution, and values and equity in environmental relations. They illuminate similarities, differences, and diversities among past and present human experiences with natural processes and objects, whether those are now approached from a current analytical perspective or from as much as can be reconstructed of a medieval stance where central concepts were not as today’s. Medieval environmental history also makes another contribution: its methods of drawing robust inferences about past events and conditions from surviving verbal and material artefacts and from traces preserved in nature constitute a call for enlarging interdisciplinarity in medieval studies. Respectful collaboration among medievalists, environmental scientists, and palaeoscientists is necessary to recapture lives, thoughts, and activities of medieval Europeans and the evolution of European nature in millennia before our own. By trying to exemplify what is known or reasonably surmised and what might be worth exploring, the present book advocates cooperation and shared learning among humane and scientific investigators, neophyte and veteran alike.