Money could be as essential to everyday life in medieval England as it is today, but who made the coinage, how was it used and why is it important? This definitive study charts the development of coin production from the small workshops of Anglo-Saxon and Norman England to the centralised factory mints of the late Middle Ages, the largest being in the Tower of London. Martin Allen investigates the working lives of the people employed in the mints in unprecedented detail and places the mints in the context of medieval England's commerce and government, showing the king's vital interest in the production of coinage, the maintenance of its quality and his mint revenue. This unique source of reference also offers the first full history of the official exchanges in the City of London regulating foreign exchange and an in-depth analysis of the changing size and composition of medieval England's coinage.