This research looks to present a reinterpretation of medieval forests, the least well understood landscapes of medieval Western Europe. The thesis focuses on the Forest of High Peak and Sherwood Forest and seeks to address several key themes, including the diversity of forest landscapes, the long-term impact of Forest Law, and evidence for power-relations and social dynamics within the forests. A wide variety of sources are utilised within this research, including map analysis and regression techniques, analysis of material culture, documentary sources, place names, church architecture, and funerary monuments. Evidence is found for forests having had a dynamic landscape character, including not only woodland, but also moorland, farmland, industrial areas, and urban areas, as well as a range of human activities that included mining, glass and charcoal manufacture, ironworking, leatherworking, carpentry, construction, and intensive arable and pastoral farming. Far from being universally oppressive, it emerges that through its protection of woodland Forest Law also preserved common rights and areas of royal demesne, the impact of which was a high degree of peasant agency during the medieval period.