In post-WWII France, a peculiar historical experiment was led by a small group of people who identified themselves as world citizens. They aimed at establishing a world representation of peoples that would work as a precondition for a sustainable global peace. One of the means they used to try to fulfill this objective was the “mundialization” of the territories, by which towns and cities could proclaim their belonging to the world. Studying the mundialization of the French town of Cahors during this period drives us to reflect upon the “mondialiste” lexicon of these experiments, upon the almost complete contemporary forgetting of this political enterprise, as well as its implicit echoes in current projects aiming at reorganizing world governance.