Guigues VIII of Viennois

Guigues VIII (1309–1333) succeeded his father John II as dauphin of Viennois in 1318, under the regency of his uncle Henri, bishop-elect of Metz, until 1323. In 1323 he married Isabelle, daughter of Philip V of France, strengthening French influence in his lands.

A bold soldier, Guigues won a victory over the Savoyards at the Battle of Varey in 1325, and in 1328 fought under Philip VI at the Battle of Cassel against the Flemings. He was killed in 1333 besieging the Savoyard castle of La Perrière, and was buried in Grenoble, leaving the Dauphiné to his brother Humbert II.