The euro crisis has been an existential crisis for Europe and for its stateless currency. It substantially impacted the institutional evolution of Europe’s Economic and Monetary Union (EMU), making EMU’s rules-based logic tumble and triggering an institutional capacitybuilding. The euro crisis period should therefore be regarded as the most constitutionally relevant post-Maastricht European integration moment. This dissertation claims that the euro crisis management, because it involved the adoption of an array of significant fiscal rules, instruments, mechanisms and bodies, has resulted in the institutionalization of a distinctive fiscal authority in Europe. The convoluted process through which this authority has emerged was characterised by a tension between countervailing forces of centralization and fragmentation. This dissertation hence conceptualizes, documents and interprets the logic of a singular institutionalization process in which new fiscal powers became concomitantly centralized, fragmented and delegated to a series of ad hoc bodies operating in the shadow of newly empowered EMU executive institutions. The centrifugal delegation pattern at play is intriguing because it runs against the classic, pre-Maastricht delegation trend that entrusted the European Commission with newly centralized tasks. The new fiscal centre is instead fundamentally fragmented among three key actors: the Eurogroup, the European Central Bank and the Commission. Indeed, the dissertation has found that despite the emergence of a fiscal centre, the European Union still does not dispose of a formalized and settled fiscal power structure. The main puzzle uncovered by this examination is that while a fiscal authority has been institutionalized, no political EU actor has been able to formally embody and exclusively claim this authority. Going forward, formalizing such a political authority would require some form of constitutional settlement to clarify who is Europe’s fiscal primus inter pares.