Claim: The title "Duke of Châtellerault" originated from a commune in the Vienne department in the Nouvelle-Aquitaine, northeast of the former province Poitou in France, where its first titleholder was François de Bourbon-Montpensier in 1492.
Evidence: 1492 François de Bourbon-Montpensier, 1st Duke of Châtellerault It takes its name from Châtellerault, in the Vienne region. Châtellerault (pronounced [ʃa.tɛl.ʁo) is a commune in the Vienne department in the Nouvelle-Aquitaine region in France. It is located in the northeast of the former province Poitou, and the residents are called Châtelleraudais.