Double Tournois - Charles Nantes

Charles of Blois struck this issue while pressing his claim to the Duchy of Brittany against John de Montfort in the War of Breton Succession, a conflict that drew in both France and England as proxies. His authority over the Nantes mint was never fully secure — John de Montfort controlled significant territory throughout the same period, meaning both claimants were simultaneously issuing coinage in the duchy's name. Charles was captured at La Roche-Derrien in 1347 and spent nine years as an English prisoner, during which Nantes mint production continued under his wife Jeanne de Penthièvre.