Castles served as government centers as well as fortresses. Walls and towers provided the necessary security especially when a ruler attempted to control rebellious subjects. Within the walls, however, were increasingly splendid residences, especially a great hall where the ruler or local lord sat in state to administer justice and hear petitions. Towers served as strong rooms to protect treasure and documents. Increasing reliance on money and laws required a treasury and legal archives for records and charters. Whereas once the scribes worked in monastic scriptoria, now they labored in chancery halls. Not only the king but also his great vassals and their vassals in turn, right down to the local officials, needed imposing and secure headquarters. Chapter 3 explores the castleís political and economic role.