It existed as an entity in the Middle Ages from at least the 10th Century, later passing to the Counts of Valentinois and the Bishop-Counts of Die (or Diois) before both were incorporated into Dauphiny proper.

In the 15th century, Dauphiny of Viennois at the head of House de La Tour du Pin, presented several conflicts in pursuit of absolutist Capet-Valois policy.

It was fortunate for France that Humbert II de la Tour-du-Pin [Wikidata], last Dauphin of Viennois, had been incompetent and extravagant, lacking the warlike ardour of his brother Guigues VIII.

How Dauphine he depleted his treasury funding a vain Crusade to rescue the Holy Land, failuring at all in his propose and after the death of his only son André and without issue and being an incompetent and luxurious man, he decides sale his patrimony to the best offer.

In 1498 and more than a century after, Louis XII of France divided Dauphiny lands and delivered Valence, Diois, Grenoble in quality of Dukedom and Counties at Cesar Borgia when Pope Alexander VI gave his support in pursuit of defense of great feudal lords and because annulled his marriage with Joan and instead married Anne of Brittany, the widow of his cousin Charles VIII.