John II of Viennois explained

Jean II de la Tour du Pin (1280 – 5 March 1319) succeeded his father Humbert I as dauphin of Viennois from 1306 to 1318. His mother was Anne of Burgundy, dauphine du Viennois.

In 1296 he married Beatrice of Hungary, daughter of Charles Martel of Anjou, titular king of Hungary, and his wife Klementia of Habsburg. They had two children:

• Guigues VIII (1309 † 1333), dauphin of Viennois.
• Humbert II (1312 † 1355), dauphin of Viennois.

References

• Book: Georgiou, Constantinos . Crusades . Ordinavi armatam sancte unionis: Clement VI's Sermon on the Dauphin Humbert II of Viennois's Leadership of the Christian Armada against the Turks, 1345. 15 . Benjamin Z. . Kedar . Jonathan . Phillips . Jonathan . Riley-Smith . Nikolaos G. . Chrissis . Routledge . 2017 .