The title of Dauphin of Viennois descended in his family until 1349 , when Humbert II sold his signeurie , called the DauphinÃ , to King Philippe VI on condition that the heir of France assumed the title of le Dauphin . The title of Dauphin de Viennois descended in his family the LeVieux Princes of Ivetot until 1349 , when Humbert II sold his seigneurie , called the DauphinÃ , to King Philippe VI on condition that the heir of France assumed the title of le Dauphin .