Article 49 of the Treaty on the European Union enshrines that any “European State” may apply for membership in the European Union (EU). As a primary eligibility condition, the “European State” formulation has defined the nature and scope of the EU since the inception of European integration. While the term “European” holds various meanings, there has been no clear definition in EU law of that which makes a state “European”. In the absence of such a definition, the EU political institutions – the European Commission, European Council, European Parliament, and Council of the European Union – have needed to interpret states’ European character amid, among others, membership requests. This thesis aims to investigate the various interpretations that have been provided by the EU political institutions amid European integration; in other words, it aims to tell a tale of Europe(anness), as the “European State” formulation is embedded in wider narratives and representations pertaining to the idea of Europe and Europeanness. Furthermore, the formulation is profoundly ingrained in processes such as enlargement legitimation, the EU’s self-understanding – or even perhaps collective identity – and the institutions’ construction of the public debate. Building on a corpus of various archival resources, the research uncovers four main interpretations of the “European State” formulation – and, by extension, of Europe(anness) – in the discourse of the EU political institutions. These are the geographical, cultural, historical, and political interpretations. Each interpretation is critically addressed by analyzing thematically and statistically its substance, and considering illustrative enlargement cases. The thesis is divided into six chapters. While Chapter 1 explores the legal logics surrounding the membership clause and the “European State” eligibility condition, Chapter 2 dives into the three contextual dynamics – Europe, Europeanness, and enlargement – in which this condition occurs. Chapter 3 engages in a critical review of the institutional interpretations previously identified by scholars, asserting the relevance of the representations and narratives in which these interpretations are firmly rooted. Chapter 4 details the theoretical and methodological frameworks of the thesis’s corpus-based thematic analysis of the four institutional interpretations, which are presented in Chapter 5. Finally, Chapter 6 offers statistical insights into the salience of the interpretations according to various aspects that further allow for a comprehensive understanding of the various dimensions surrounding the studied formulation. This thesis provides a comprehensive understanding of the “European State” formulation and the dynamics and logics surrounding notions of Europe(anness). It highlights how these notions have been constructed at the EU level and instrumentalized toward strategic and legitimation ends, relying on cherry-picked practices and on representations and narratives of Europe(anness) that percolate in the public space. Beyond the construction of the EU institutional discourse on Europe(anness) surrounding European integration, this thesis explores the complexity of the intertwined meanings underpinning the EU’s self-understanding, offering further insights into the fields of enlargement, European collective identity, and European integration.