This dissertation explores the way that the environment, both tangible and imagined, influenced and shaped medieval culture and society. It surveys the social and political history and religious culture of the monasteries of Stavelot and Malmedy, in the Ardennes (modern Belgium). Administrative documents show that the forested landscape of the Ardennes influenced the monasteries' economic decisions and social relations. The religious sources---such as miracle stories and saints' lives---show that control of the environment was also culturally and religiously significant.