French High Courts embraced review of national legislation for conformity with EU law in different stages and following distinct approaches to EU law supremacy. This article tests whether adherence to different views on EU law supremacy has resulted in different levels of EU directive enforcement by the French High Courts. After introducing the complex French systems of statutory, treaty and constitutional review, this study explains how EU-conformity review emerged among these systems and provides an empirical analysis refuting the anecdotal view that different EU supremacy theories produce substantial differences in conformity adjudication outcomes. These Courts' uniformly high rates of EU directive enforcement and similar willingness to refer questions to the ECJ for preliminary rulings demonstrate that, despite adopting dissimilar approaches to the supremacy of Communitarian law, French judges have flourished as Communitarian law judges. The article concludes by presenting an explanation for this high degree of convergence: French judges, responding to growing European integration and enabled by a changing constitutional landscape, adjusted their views to ensure they would have a role in molding the integration of national and EU law.