This section aims to provide graphic materials about some general aspects of European Union: schemes on the current priorities of the European Comission, differences in GDP or population between the different European countries, historical evolution of the integration process, etc.
First of all, it is important to take into account the historical evolution of the integration process. Its origins go back to the creation of the European Communities in the 50s. In 1951, in the Treaty of Paris, 6 European states (Germany, France, Italy, Luxembourg, Belgium and the Netherlands) agreed to the creation of the ECSC (Community Economic of the Coal and the Steel). In 1957, under the Treaty of Rome, these same states decided the creation of the European Economic Community and EURATOM. From the 1950s up to now, there has been 6 enlargements and a series of revisions of the treaties have been followed by giving more powers to the European institutions.
The current concept of the European Union is created in the Maastricht Treaty. The treaties currently in force are the result of the latest reforms that have their origin in the Lisbon Treaty of 2007. The biggest enlargement was that of 2004, with the addition of 10 countries.
In order to understand this extension, you can check a conceptual chart of the process that lead to reach the "Great Expansion".