The European Union (EU) is an organization that consists of 28 members. It traces its origins from the European Economic Community, invested at the 1952 Treaty of Paris.
By 1995, the EU has consisted of 15 members: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden and the UK. In 2004, the EU saw its biggest enlargement to date when Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia and Slovenia joined the Union. Newer members are Bulgaria, Romania (in 2007) and Croatia (in 2013).
The EU has 7 institutions: the European Council which is a council of Heads of States and Governments of the Member States; the European Commission, the Executive Branch; the Council of the European Union, the Upper House; the European Parliament, the Lower House; the Court of Justice of the European Union, the Judiciary; the European Court of Auditors, the Financial Auditor; and the European Central Bank, governing the supply of euro.
An important part of the EU is the Eurozone, a monetary union with 17 members who choose to adopt a common currency, the Euro. The Euro was established in 1999 with 11 members. Estonia is the newest of the 17 states. 9 of the other 11 member states (except for Denmark and the UK) are obliged to join the Eurozone, including Latvia and Lithuania. These two states are members of the ERM II, along with Denmark, choosing to loosely peg their currency to the Euro in a 15% deviation from the central rate. Latvia will enter the Eurozone on January 1st, 2014.
Apart from the Eurozone, the EU developed a single market through a standardised system of laws that apply in all member states. Also, the Schegen Area, originally established outside of the then European Community, now absorbed into the EU, consisting of 22 EU and 7 non-EU states, abolish the passport and immigration controls along their borders.
EU is currently considered the highest structured regional organization in the world.