VALENTINOIS  , the name of a countship in

France, the chief town of which was Valence (Dr8me) . From the 12th to the 15th century Valentinois belonged to a family of Poitiers, which must not be confused with that of the counts of Poitiers . To the detriment of his kinsmen, the lords of St Vallier, Count Louis II . (d . 1419) bequeathed his counties of Valentinois and Diois to the Dauphin Charles, afterwards King Charles VII.; and in 1498 Louis 'XII. erected the countship of Valentinois into a duchy, and gave it to Caesar Borgia, son of Pope Alexander VI . A few years later Borgia was deprived of the duchy, which, in 1548, was given by Henry II. to his mistress, Diane de Poitiers, a descendant of the counts of Valentinois . Having again reverted to the Crown, the duchy was given by Louis XIII. to Honore Grimaldi, prince of Monaco, whose descendants retained it until the French Revolution . The new duchy of Valentinois, however, did not consist of the lands attached tothe former one, but was made up of several scattered lordships in Dauphine . The title of duke of Valentinois is still borne by the prince of Monaco . See J . Chevalier, Memoires pour servir a l'histoire des comas de Valentinois et de Diois (Paris, 1897—1906) .