This chapter will attempt to observe the constraints and cleavages faced by cities' organizations, through the place and role that a single city has made for itself in their midst. Lyon, France's “second city”, offers both archival, direct observation and oral interview opportunities to bridge a century of intermunicipal activities, because of its presence in several organizations across different generations. Amongst those we have selected is the oldest transnational association of municipalities, the Union Internationale des Villes, created in 1913, and the more contemporary Eurocities, founded in Barcelona in 1989. We believe the comparison between the role of Lyon within these two groups can help us to understand both the nature of the city's protagonism beyond the national sphere, and the basis on which such municipal associations operate, as well as how these change, or exhibit continuities, across time and space.