 He spent much of his first few years as count at war with the Dauphin, Guigues VIII of Viennois, continuing a feud which went back for generations in their families.After Guigues was killed besieging La Perrière in 1333, Philip VI of France was able to broker a truce between Aymon and the new Dauphin, Humbert II of Viennois, brother of Guigues.In August 1334, in the buildup to the Hundred Years' War, Edward III of England sent an embassy to Aymon to convince him to join the impending conflict on the side of the English.