By and large, the history of the European Union (EU) is that of a functionalist integration process. To the disappointment of all those who advocated the construction of a fully fledged federalist polity, with clearly defined supranational institutions, there has never been a clear constituting moment, with something like a general assembly of Europeans, that has then given rise to a common European polity. Instead, there have been a series of international treaties, which have instituted first the European Coal and Steel Community (ECSC), with its six member states, and, then, after a series of intermediate passages, the current EU, with its twenty-seven member states.
Historically, the European construction can be compared to a growing kernel, always spilling over into new sectors. The core of this kernel is the ECSC, established in 1952, which grew into the European Economic Community (EEC) and the European Atomic Energy Community (also referred to as EURATOM), with the Rome Treaty in 1957. In July 1987, the Single Act merged these communities into one body, the European Community (EC). Over this founding period, the European Parliament moved from a consultative assembly, to which national parliaments sent a few delegates in charge of overseeing the work of the nascent European executive, into a representative European Parliament elected directly, since 1979, by European citizens. At that time, it was clear that Europe was becoming more than a market space.