French: from a medieval personal name (Latin Delphinus, from delphis ‘dolphin’). This name was borne by a 4th-century saint who was bishop of Bordeaux, and from the early 12th century it was in use as a hereditary personal name in the family of the counts of Albon, so that it soon came to be used as a title and led to their territory (capital Grenoble) being known as the Dauphiné. When it became part of the Kingdom of France in 1349, the title of dauphin thereafter denoted the heir-apparent to the throne, and it is possible that in some cases this is the origin of the surname, either denoting a member of the Dauphin’s household or applied as a nickname in the sense of ‘prince’.