In AD 943, the treaty of Verdun divided up the empire of Charlemagne. The river Saône became the frontier between France and the Empire. It is thanks to this border location that Trévoux gained its particular political status.

In AD 943, the treaty of Verdun divided up the empire of Charlemagne. The river Saône became the frontier between France and the Empire. It is thanks to this border location that Trévoux gained its particular political status.