Book excerpt: This fascinating study of medieval warfare examines the vital role of castles during the English civil wars of the 15th century. The Wars of the Roses comprise one of the most fascinating periods in medieval history. Much has been written about the leading personalities, bitter dynastic rivalries, political intrigues, and the rapid change of fortune on the battlefields of England and Wales. However, there is one aspect that has been often overlooked, the role of castles in the conflict. Dan Spencer’s original study traces the use of castles from the outbreak of civil war in the 1450s during the reign of Henry VI to the triumph of Henry VII some thirty years later. Using a wide range of narrative, architectural, financial, and administrative sources, Spencer sheds new light on the place of castles within the conflict, demonstrating their importance as strategic and logistical centers, bases for marshaling troops, and as fortresses.