Guillaume de Joinville

Guillaume de Joinville (c. 1256 – after 1324) was a son of Simon de Joinville and Léonète, heiress of Gex, and founder of the Joinville-Gex line. Already lord of Gex by 1287, he rendered liege homage to Count Amédée V of Savoy in 1289.

The town's franchises were sealed in 1292, and in 1305 he bought the tower of La Maladière and the castle of Tougins. By Jeanne de Savoie he left a son, Hugues, and a daughter, Éléonore, heiress of Gex.