The European Union (EU) is a political and economic union of 27 European countries whose members have conferred specified powers on common institutions through treaties. It combines cooperation between national governments with institutions that legislate, administer policies, and interpret common law. Its activities include a single market, international trade, environmental protection, and a common currency used by most members. The EU’s stated foundational values include democracy, the rule of law, and respect for human rights. (enjoy-its-from-europe.campaign.europa.eu)
Historical development
European integration developed after World War II, initially through cooperation intended to reduce conflict and rebuild economic relationships. Belgium, France, West Germany, Italy, Luxembourg, and the Netherlands signed the treaty establishing the European Coal and Steel Community in 1951; it entered into force in 1952. The Treaties of Rome, signed in 1957 and effective from 1958, established the European Economic Community and the European Atomic Energy Community, extending integration beyond coal and steel. (op.europa.eu)
The Maastricht Treaty, signed in 1992 and effective on 1 November 1993, established the European Union. It introduced Union citizenship, expanded political cooperation, and provided the framework for monetary union. The Treaty of Lisbon, effective from 1 December 2009, subsequently amended the founding treaties, strengthened Parliament’s role, and revised institutional arrangements and voting procedures. (european-union.europa.eu)
Successive enlargements extended membership beyond the original six countries. Ten states joined in 2004, followed by Bulgaria and Romania in 2007 and Croatia in 2013. The United Kingdom withdrew on 31 January 2020 in the process known as Brexit, leaving 27 member states. (european-union.europa.eu)
Institutions and decision-making
The EU has seven principal institutions, with responsibilities divided among political direction, legislation, administration, adjudication, monetary affairs, and financial auditing. Their main locations include Brussels, Strasbourg, Luxembourg, and Frankfurt. (european-union.europa.eu)
The European Parliament represents citizens and is directly elected every five years. The Council of the European Union represents member governments through national ministers, meeting in different configurations according to the policy area. These institutions jointly adopt most EU legislation and the budget. The European Commission generally proposes legislation, administers policies and spending, and monitors compliance with EU law. (european-union.europa.eu)
The European Council, bringing together member states’ heads of state or government, sets broad political priorities rather than ordinarily legislating. The Court of Justice of the European Union interprets EU law and reviews compliance with treaty obligations. The European Central Bank conducts monetary policy for the euro area, while the European Court of Auditors examines EU finances. (european-union.europa.eu)
Under the ordinary legislative procedure, Parliament and the Council consider Commission proposals and must agree on the legislative text. Other procedures apply where the treaties specify them. National authorities implement many EU policies, so administration operates through both Union institutions and member-state institutions. (commission.europa.eu)
Legal framework and powers
The EU’s authority rests on its founding treaties. Under the principle of conferral, it may act only within powers granted by member states. Subsidiarity governs action outside exclusive EU competences: Union intervention must be justified by objectives that can be better achieved at Union level. Proportionality requires that action not exceed what is necessary to achieve treaty objectives. (commission.europa.eu)
Exclusive competences include the customs union, common commercial policy, specified competition rules, and monetary policy for euro-area countries. Shared competences include the internal market, agriculture, environmental policy, transport, and energy. In areas such as education and culture, the EU principally supports or coordinates national action. (commission.europa.eu)
EU legislation takes several forms. Regulations are binding in their entirety and directly applicable across member states. Directives establish results that states must achieve, generally through national implementing measures. Decisions are binding on their specified addressees where addressees are named; recommendations and opinions are not legally binding. (european-union.europa.eu)
Economic integration and policies
The single market is organized around the free movement of goods, services, capital, and people. Common rules address cross-border business, product standards, consumer protection, and other matters affecting economic exchange. The customs union removes internal customs duties and applies common customs arrangements to goods arriving from outside the Union. (european-union.europa.eu)
The euro began as a currency in 1999, with banknotes and coins introduced in 2002. Bulgaria adopted it on 1 January 2026, bringing the euro area to 21 EU members. Monetary policy is conducted through the European Central Bank and participating national central banks; euro membership is distinct from EU membership. (european-union.europa.eu)
The EU budget finances common priorities, including regional development, agriculture, research, infrastructure, and external action. Spending is administered through a combination of Commission management, national authorities, and partner organizations, with institutional auditing and parliamentary scrutiny. (european-union.europa.eu)
Membership and movement
Accession requires satisfaction of the Copenhagen criteria: stable democratic institutions, protection of rights and minorities, a functioning market economy, and the capacity to implement EU obligations. Negotiations examine the candidate’s alignment with EU law. Admission requires parliamentary consent, unanimous Council approval, and ratification of an accession treaty by the contracting parties. (consilium.europa.eu)
The Schengen Area removes routine checks at participating countries’ internal borders, subject to legal provisions permitting temporary controls. It is not identical to the EU: it includes non-EU countries, while not all EU members participate fully. Bulgaria and Romania’s internal land-border controls were lifted on 1 January 2025. (consilium.europa.eu)