ABSTRACT
The adoption of a single currency by twelve of the fifteen countries of the EU on 1 January 2002 was a major step forward in the process of European integration. The Euro exerted further pressure on the EU to become a supranational polity, rather than, or more than, an international organization. Moreover, the single currency concluded a process of integration that has been largely driven by economic factors and promoted by legal actors (primarily the European Court of Justice). It was the gradual formation of a common market which gave substance to the project of integration. The need to build a continental economic space without national barriers and open to transnational competition introduced a systemic mechanism of change into the economies of the EU member states. The two Rome treaties of 1957, especially, engendered a dynamic process of successive changes which eventually gave rise to the transfer of internal monetary sovereignty into a supranational financial institution: the European Central Bank. But it was the European Court of Justice (ECJ), as Alec Stone Sweet explains in his chapter, with its interpretation of the Rome treaties as quasi-constitutional documents, that transformed those treaties into compelling arguments for the dismantling of national barriers to the formation of a continent-wide market.
