Duke of Valentinois is a title of nobility, originally in the French peerage. It is currently one of the many hereditary titles claimed by the Prince of Monaco despite its extinction in French law in

Florestan was Prince of Monaco and Duke of Valentinois from 2 October 1841 until his death in 1856. He was the second son of Prince Honoré IV and Louise d'Aumont Mazarin and succeeded to the throne on