When the Treaty of Rome (the Treaty) was signed, the legal profession believed it had no impact on its organisation. Yet, from the very beginning, the Directorate General (DG) Internal Market started to work on a directive that would facilitate the circulation of lawyers within the European market. This article is based on the analysis of the 16-year debates leading up to the adoption of the 1977 Directive, which facilitate the effective exercise by lawyers of freedom to provide services. It adopts a bottom-up, actor-centered approach, to understand the role of lawyers and the importance of legal professions in the construction of the common market. Using archival study, interviews and legal analysis, the article shows that the integration of European legal professions cannot be understood without studying the historical structures of each national profession. Moreover, the rallying of lawyers to the European project can only be attributed to the active interpretative work of multipositioned actors.