In one of the great classical analyses of the early development of European law, American legal scholar, Eric Stein, argued that the legal service of the EEC Commission and its director Michel Gaudet were the originators of the groundbreaking interpretation of the Treaties of Rome, which the Court of Justice adopted in the famous cases Van Gend en Loos (1963) and Costa V. ENEL (1964). These two cases, which introduced respectively direct effect and supremacy of European law inside the national legal order, would over time develop into the central pillars in what is now most often characterised as a ‘constitutionalised’ European legal order. Recent historical and social science research in the early history of European law has highlighted the central role of the legal service and Michel Gaudet in the development of increasingly dense transnational networks of European minded jurists supporting and legitimising the jurisprudence of the Court of Justice. However, it has not yet been able to refute or confirm Stein’s thesis. In fact, our knowledge about the legal service of the European executives (i.e. the legal service of the High Authority from 1952-1958 and the common legal service for all three executives from 1958-1967) is still fairly limited. Historical literature on the history of the European executives has largely ignored the legal aspects of the European administration and the nature of the legal service.

This paper, which is based on until now unused primary sources from the Commission archive as well as several key private archives, consequently constitutes the first attempt to write a history of the legal service of the European executives from 1952 to 1967. With the functions and actions of the legal service being very far from the public spotlight, the story presented here has until now been completely unknown. The first half of the article will as a consequence offer the reader an overview of the people, organisation and functioning of the legal service in the period covered. The second half will then address the role of the legal service in the establishment and development of European law in order to finally be able to affirm, reject or nuance Stein’s classic claim.