Constitutionalization in Question: Revisiting the Foundational Logics of European Integration by Law Today it is a widely accepted view within the core disciplines of European studies, law and political science, that the Court of Justice has constitutionalized the Treaties of Rome and created a veritable constitution of a quasi-federal nature. By introducing direct effect of European law (Van Gend en Loos, 1963) and supremacy of European law vis-à-vis national law (Costa v. ENEL, 1964), and allowing preliminary references from national courts that dealt explicitly with the junction of national and European law (article 177), an enforcement mechanism of European law was created. This in turn, so the story goes, transformed the Treaties into a catalogue of rights for national citizens. As a result, the citizens of Europe have been able to deepen integration by the means of law and a rule of law has been established in the European Union. This explanation of the history of European law first developed in the mid-1960s in legal commentary that by and large legitimised the seminal judgments by the Court of Justice. By the early 1980s, as a result of the contributions of Eric Stein and the famous Integration-through-Law project (Cappelleti and Weiler), it developed into a full-fledged scientific paradigm, which most legal scholars analysing European law would share. With the famous Maastricht judgment of the German Constitutional Court in 1993, the legal science further developed the paradigm into an increasingly diverse and sophisticated understanding of exactly what type of constitution the European Union had or in what ways European law were constitutional. In addition, political scientists have since the 1990s analysed the history of European law as well as processes of Europeanization through the concepts of the integration-through-law project. The premise of this conference is that the constitutionalization paradigm has played a key role in legitimating the case law of the Court of Justice. Recent historical and sociological research on the history of European law of European law has highlighted how the paradigm emerged as a central element in a broader struggle over how European law should evolve in the 1950s and 1960s. The establishment of the paradigm thus represented a strategy to create a new field of law separate and independent from both national and in particular international law. As a sociological process the construction of the new paradigm was similar to the classical establishment of a new field of law, however, due to the political fragility and the disputed nature of the European project, this was considered extremely controversial. The key ambition of the conference is thus to take the constitutionalization paradigm as the object of study. Paper contributors will explore various aspects of the paradigm. What was its history? How did it emerge and develop over time? What sociological mechanisms cemented the paradigm and what role did it play in the broader development of European law and particular in legitimating the case law of the Court of Justice? What were the politics of constitutionalization? Did it empower the European institutions vis-à-vis the member states and to what extent was it met with resistance by national institutions and courts? What was the development in legal thinking that shaped the paradigm? Who were the key figures promoting the paradigm? To what extent did critics of the paradigm manage to shape debates? Organisation The conference is organised by the research network: Rethinking European Integration, (https://cemes.ku.dk/rethinking_european_integration/) Centre of Modern European Studies, Faculty of Humanities (CEMES) and Centre for Studies in Legal Culture, Faculty of Law (CRS) both University of Copenhagen. It is funded by EURECO (www.eureco.ku.dk), a research excellence initiative at the University of Copenhagen. The conference is moreover held in collaboration with RICHIE and POLILEXES. The RICHIE network is organised with the expressed aim to establish the history of European law as a distinctive field of research, identify possible archival resources, construct methodological frameworks and eventually write histories of European law that not only fill in the current gap in historiography, but also contribute to on going legal and social science research in European law. POLILEXES is an established research collective which has pioneered the study of the agency of European legal integration, thereby significantly redefining the object of inquiry in legal and social scientific studies of European integration.