This chapter analyses the market as part of social and constitutional imaginaries and economic rationality and communication based on the code of profit. It argues that the EU's economic constitution is imagined as the spontaneously self-evolving imperium of prosperity and peace promoted by market collaborations and competition. It argues that the constitution of the European common market was to generate the common wealth for all parties and its instrumental mode of consociation was to institutionalise common political interests and bonds beyond national economies and states. It subsequently revisits theoretical contributions and conceptualisations of the German school of ordoliberalism to further contextualise recent debates of the European economic constitution. The common market and wealth were to inspire the constitution of a transnational polity legitimised by the economic value of prosperity as much as shared political values of democracy, freedom, rights and peaceful coexistence of the multitude of European peoples and citizens. The chapter, therefore, concludes by arguing that the imaginary of the spontaneously self-constituting imperium of prosperity, which evolves as structural coupling between European economy, politics and law, operates as background power of EU economic constitutionalism in its both microeconomic and macroeconomic regimes.