is a title which was given to the eldest son of the royal family of France, and presumptive heir of the crown; on account of the province of Dauphiné, which in 1343 was given to Philip de Valois, on this condition, by Humbert dauphin of the Viennois. The dauphin, in his letters patent, styled himself, By the grace of God, eldest son of France, and dauphin of Viennois.

Dauphin was anciently the title or appellation of the prince of Viennois in France.

Most authors who have sought the origin of the name Dauphin and Dauphine, seem to have given too much loose to conjecture. Du Chesne is of opinion, that it was the grandson of Guy the Fat who first bore the name of dauphin. Chorier observes, that William, canon of Notre Dame at Grenoble, who has written the life of Margaret, daughter of Stephen earl of Burgundy, married with Guy, son of Guy the Fat, calls the latter simply Guy the Old, and the former always Count Dauphin; and adds, that no record or monument ever attributes the title of dauphin to Guy the Fat, or any of his predecessors: so that it must necessarily have taken its rise in his son, all whose successors so constantly assumed it, that it became the proper name of the family. He died in 1142, in the flower of his youth; so that it must be about the year 1120 that the title commenced; and without doubt, adds he, on some illustrious occasion. He observes farther, that this prince was of a military disposition, and delighted in nothing but war: and again, that it was the custom of the cavaliers to deck their casques, coats of arms, and the housing of their horses, with some figure or device peculiar to themselves, whereby they were distinguished from all others engaged in the same combat or tournament. From all these circumstances he conjectures that this Guy chose the dolphin for his signature; that this was the crest of his helmet; and that he bore it on his coat in some notable tournament or battle, wherein he distinguished himself. And this, Chorier makes no doubt, is the real origin of the appellation. Nothing was more common in those times than to make proper names become the names of families or dignities. Witness the Ademars, Arthands, Aynards, Attomans, Berengers, and many others; who all owe their names to some one of their ancestors, from whom it has been transmitted throughout the family.

The seigneurs or lords of Auvergne have likewise borne the appellation of dauphin; but the dauphins of Auvergne had it not till a good while after those of the Viennois, and even received it from them. The manner was this: Guy VIII., dauphin of Viennois, had by his wife Margaret, daughter of Stephen earl of Burgundy, a son and two daughters. The son was Guy IX., his successor. Béatrix, one of the daughters, was married to the count d'Auvergne, who, according to Blondel, was William V. or rather, as Chorier and others hold, Robert VI., father of William V. This prince lost the greatest part of the county of Auvergne, which was taken from him by his uncle William, assisted by Louis the Young: and was only left master of the little canton whereof Vodable is the capital. He had a son whom he called Dauphin, on account of Guy, or Guignes, his uncle by the mother's side. From his time his successors, holding the same petty canton of Auvergne, styled themselves dauphins of Auvergne, and bore a dolphin for their arms.