European Union

The European Union is a supranational political and economic union, which includes 27 member states. Born as the European Economic Community with the Treaty of Rome of 25 March 1957, during a long integration process, with the accession of new member states and the signing of numerous amending treaties, including the Maastricht Treaty of 1992, it assumed its current structure with the Treaty of Lisbon in 2007.

Equipped with its own legal system, distinct from common international law and integrated into the internal law of the member states, its institutional architecture and its competences make it similar in some respects to a federal state, in others to a confederation of states, for which is often referred to in doctrine as a sui generis organisation, of a different nature both from state constitutional law and from classic interstate international law.