Based upon extensive multi-archival research, this article traces the long lineage of the notion of European electricity network. Since the 1930s engineers and policy makers conceived of a geographical conception for rationalising and optimising electricity supply: a European one. This article purports that three vectors undergirded threads of continuity: institutional, intellectual and physical (technological networks). These vectors, and the actors involved in them, created strong path dependencies that kept the idea of a European system firmly on the agenda. Today's international electricity market of the European Union should be seen as an extension of this legacy.