This book examines the impact of military events on Nottinghamshire's landscape from prehistoric hill forts to Cold War bunkers. Straddling the valley of the Trent, Nottinghamshire has long enjoyed a strategic importance as a frontier region in the early days of the Roman conquest, and during the struggles between the emerging Saxon kingdoms and the Danes. The Normans built castles to pacify the land, as did the kings and barons involved in the dynastic struggles which characterised long periods of medieval times. Throughout the Civil War it provided a battleground for Parliamentarian forces seeking to sever the Royalist communications centred on Newark-upon-Trent. In the twentieth century it provided training camps for Kitchener's New Armies, munitions factories, and both training and operational airfields. This book describes the evidence, function and purpose of defensive structures and records survivals.