The European Union (EU) is a political and economic union of 27 member states located primarily in Europe. It has a total area of about 4.2 million square kilometres and a population of just under 452 million as of 2026. Its member states generated a nominal GDP of around €18.8 trillion in 2025, roughly one sixth of global economic output. The EU is often described as a unique political entity combining features of both a federation and a confederation.
Single market and policies
The EU's cornerstone is the Customs Union, which led to an internal single market based on common legal standards applying in areas where member states have agreed to act together. EU policies aim to ensure the free movement of people, goods, services and capital, and to maintain common policies on trade, agriculture, fisheries and regional development. Passport controls have been abolished for travel within the Schengen Area. The eurozone comprises 21 member states that use the euro. Through its Common Foreign and Security Policy, the union also plays a role in external relations and defence, and it was awarded the Nobel Peace Prize in 2012.
Origins and development
The EU was established with its citizenship when the Maastricht Treaty entered into force in 1993, and it gained a single international legal personality under the Treaty of Lisbon in 2009. Its roots lie in the post-war European integration that began in 1948 and in earlier bodies such as the European Coal and Steel Community and the European Economic Community. Over time the union grew through the accession of further states between 1973 and 2013 and through the acquisition of new policy areas. In 2020 the United Kingdom became the only member state to leave.