The Introduction explains how the ECB was established as a central bank mainly controlled and guided by its constitutional framework. When this constitutional model has been challenged by a series of crises, the carefully designed economic constitutional model has been replaced by a constant flow of ad hoc measures that were largely responses to the economic and political realities of the moment. In the euro area, the economic, financial, sovereign debt and finally pandemic crises have also been constitutional crises. The ECB lacks a nation state’s economic and political will-formation as its counterpart and as its ultimate control. Its main counterpart is the constitutional framework, called the European Macroeconomic Constitution. This special model requires a special EU constitutional law approach to assess the ECB’s measures and to guide it going forward. It is a broadly based constitutional law methodology that could also be defined as economic constitutionalism.