This chapter provides a comprehensive historical and legal account of the evolution of EU economic governance, from the Treaty of RomeRome to the post-crisisCrisis reforms of the 2010s and beyond. It traces the development of EU economic governance as a supportive—but increasingly central—component of European integration, analysing how the original intergovernmental and technocratic framework gradually gave way to a more rule-based, supranational model, particularly after MaastrichtMaastricht. The chapter critically assesses the Stability and Growth Pact, the Eurozone sovereign debt crisis, and subsequent legal reforms, questioning the effectiveness and legitimacy of EU powers in the fiscal domain. It concludes by highlighting a persistent gap between legal form and political substance in the EU’s economic governance architecture.