Research on the Court of Justice of the European Union (CJEU) generally underlines the Court’s high degree of influence in creating “integration through law”. Supported by the major parties in European Member States, and without outward contestation from the populations of the Member States, the Treaty of Rome conceived of the Court’s role as one of interpreting and assessing the validity of European law. The Court later went beyond these legal bases, but was, despite resistance from some national courts and Member State governments, considered legitimate to fill the political and legal void in this new supranational order. This understanding of the Court, which was first based on analyses by Stein (1981), Weiler (1981) and Cappelletti et al. (1986), has been further built upon by a number of scholars who share a common perception of the Court as a creator of norms and European’s “judge-made law” (Alter and Meunier-Aitshalia, 1994; Armstrong, 1998; Alter, 2007; Vauchez, 2008). Today, the EU is considered as one of the most highly institutionalized supranational political systems in the world, a system developed, in particular, through the decisions taken by the CJEU (Stone Sweet and Caporaso, 1998; Stone Sweet and Brunell, 1998; Stone Sweet, 2000; Alter, 2001, 2009; Kelemen, 2011, 2016, Blauberger and Schmidt, 2017). It has, as Kathleen McNamara pointed out, created a “banal authority” in the EU’s political system (McNamara, 2015, 3). Thus, the CJEU can be perceived as having highly contributed to shaping the EU integration process and has even been criticized for being an activist Court (Beck, 2012; for an answer to this critique: Grimmel, 2014)