Bishops of Durham had the right to mint coins from the late eleventh century to the mid-sixteenth century. Many thousands of these coins survive, and more are found each year. This book, which is the first to be published on the Durham mint since 1780, places the coins in the context of the abundant manuscript sources for the history of the mint. It investigates the work of the people who ran the mint, and the mint's profits and output. This is the first comprehensive account of an English ecclesiastical mint, reconstructing its operation as a business at the mercy of market forces, and assessing its contribution to the exceptional palatine privileges of the bishops of Durham.