European integration is a complex and evolving process, explained and clarified in this book. Since its beginning with the 9 May 1950 Schuman Declaration, there have been several official names associated with the project: the 1951 Treaty of Paris created the European Coal and Steel Community; the 1957 Treaties of Rome created the European Economic Community and the European Atomic Energy Community; after the 1967 Merger Treaty, they came to be known together as the European Communities and then the European Community; and the 1992 Treaty of Maastricht changed the name to European Union. European Community also refers to the first pillar of integrated competences as established in the Treaty on European Union.
Most of the name changes are accompanied by significant advances in the European integration process. On a practical level, the constant use of different names to refer to the same process during different stages in its development can be quite confusing. Therefore, the general guidelines we followed were to refer to the European integration process prior to 1992 as the European Community, and from 1992 on as the European Union. When describing an ongoing event, process, development, etc. that has spanned both periods, we use European Union. When referring to the European Community as the first pillar of the Maastricht Treaty, we use the term “Community.”