European Union

The European Union (EU) is a politico-economic union of member states that are located primarily in Europe. It has an area of 4,324,782 km2, and an estimated population of over 510 million. The EU has developed an internal single market through a standardised system of laws that apply in all member states. EU policies aim to ensure the free movement of people, goods, services, and capital within the internal market, enact legislation in justice and home affairs, and maintain common policies on trade, agriculture, fisheries, and regional development. Within the Schengen Area, passport controls have been abolished. A monetary union was established in 1999 and came into full force in 2002, and is composed of 19 EU member states which use the euro currency.

The EU operates through a hybrid system of supranational and intergovernmental decision-making. The seven principal decision-making bodies—known as the institutions of the European Union—are the European Council, the Council of the European Union, the European Parliament, the European Commission, the Court of Justice of the European Union, the European Central Bank, and the European Court of Auditors.

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. 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. While no member state has, as yet, ever left the EU, a non-binding referendum in the United Kingdom in June 2016 supported leaving. The Maastricht Treaty established the European Union in 1993 and introduced European citizenship. The latest major amendment to the constitutional basis of the EU, the Treaty of Lisbon, came into force in 2009.

Covering 7.3% of the world population, the EU in 2014 generated a nominal gross domestic product (GDP) of 18.495 trillion US dollars, constituting approximately 24% of global nominal GDP and 17% when measured in terms of purchasing power parity. Additionally, 26 out of 28 EU countries have a very high Human Development Index, according to the United Nations Development Programme. In 2012, the EU was awarded the Nobel Peace Prize. Through the Common Foreign and Security Policy, the EU has developed a role in external relations and defence. The union maintains permanent diplomatic missions throughout the world and represents itself at the United Nations, the World Trade Organization, the G8, and the G-20. Because of its global influence, the European Union has been described as a current or as a potential superpower.

Enlargement
The enlargement is based on their criteria from 1987, with their 4 members of the family, followed by 1995 - 2 more members, 1997 - 1 more member and 1998 - 1 more member. More enlargement came from 2004 onwards.

British Brexit
A referendum on the UK's membership of the European Union (announced by British Prime Minister David Cameron on 20 February 2016) was held on 23 June 2016, following years of campaigning by eurosceptics. The result was a majority voting to leave of 51.9%, with 48.1% voting to remain, on a turnout of 72.2% of registered voters. , the UK has not yet initiated the formal withdrawal procedure, and will not leave the EU until either two years after they notify the European Council of their decision to withdraw, or on the coming into force of a withdrawal agreement.