The European Union is an economic and political union of 27 states that are located primarily in Europe. The EU operates through a system of supranational independent institutions and intergovernmental negotiated decisions by the member states. Institutions of the EU include the European Commission, the Council of the European Union, the European Council, the Court of Justice of the European Union, the European Central Bank, the Court of Auditors, and the European Parliament. The European Parliament is elected every five years by EU citizens. The EU's de facto capital is Brussels. The EU traces its origins from the European Coal and Steel Community (ECSC) and the European Economic Community (EEC), formed by the Inner Six countries in 1951 and 1958 respectively. In the intervening years the community and its successors have grown in size by the accession of new member states and in power by the addition of policy areas to its remit. The Maastricht Treaty established the European Union under its current name in 1993. The latest major amendment to the constitutional basis of the EU, the Treaty of Lisbon, came into force in 2009. The EU has developed a single market through a standardized system of laws that apply in all member states. Within the Schengen Area (which includes 22 EU and 4 non-EU states) passport controls have been abolished. EU policies aim to ensure the free movement of people, goods, services, and capital, enact legislation in justice and home affairs, and maintain common policies on trade, agriculture, fisheries and regional development. A monetary union, the euro zone, was established in 1999 and is composed of 17 member states. Through the Common Foreign and Security Policy the EU has developed a role in external relations and defence. Permanent missions have been established around the world. The EU is represented at the United Nations, the WTO, the G8 and the G-20. With a combined population of over 500 million inhabitants, or 7.3% of the world population, the EU, in 2012, generated a nominal gross domestic product (GDP) of 16.584 trillion US dollars, representing approximately 20% of the global GDP when measured in terms of purchasing power parity, and represents the largest nominal GDP and GDP PPP in the world. The EU was the recipient of the 2012 Nobel Peace Prize.
After World War II, moves towards European integration were seen by many as an escape from the extreme forms of nationalism that had devastated the continent. The 1948 Hague Congress was a pivotal moment in European federal history, as it led to the creation of the European Movement International and also of the College of Europe, a place where Europe's future leaders would live and study together. 1952 saw the creation of the European Coal and Steel Community, which was declared to be "a first step in the federation of Europe", starting with the aim of eliminating the possibility of further wars between its member states by means of pooling the national heavy industries. The founding members of the Community were Belgium, France, Italy, Luxembourg, the Netherlands, and West. The originators and supporters of the Community include Alcide De Gasperi, Jean Monnet, Robert Schuman and Paul-Henri Spaak. In 1957, the six countries signed the Treaty of Rome, which extended the earlier cooperation within the European Coal and Steel Community (ECSC) and created the European Economic Community, (EEC) establishing a customs union. They also signed another treaty on the same day creating the European Atomic Energy Community (Euratom) for cooperation in developing nuclear energy. Both treaties came into force in 1958. The EEC and Euratom were created separately from ECSC, although they shared the same courts and the Common Assembly. The executives of the new communities were called Commissions, as opposed to the "High Authority". The EEC was headed by Walter Hallstein (Hallstein Commission)...