Simon de Joinville
Simon de Joinville (died 1276) was a younger son of Simon, lord of Joinville, and Béatrice d'Auxonne. First lord of Marnay, he married Léonète in 1252, the eldest daughter and heir of Amédée II, lord of Gex, and through her acquired the barony of Gex.
In March 1258 he concluded an agreement with the convent of Saint-Victor at Geneva. His sons Pierre and Guillaume succeeded him, and Guillaume rendered liege homage to Count Amédée V of Savoy in 1289.