Euro banknotesBanknotes of the euro, the common currency of the eurozone (euro area members), have been in circulation since the first series (also called ES1) was issued in 2002. They are issued by the national central banks of the Eurosystem or the European Central Bank. The euro was established in 1999, but "for the first three years it was an invisible currency, used for accounting purposes only, e.g. in electronic payments". In 2002, notes and coins began to circulate.
Treaty of LisbonThe Treaty of Lisbon (initially known as the Reform Treaty) is an international agreement that amends the two treaties which form the constitutional basis of the European Union (EU). The Treaty of Lisbon, which was signed by all EU member states on 13 December 2007, entered into force on 1 December 2009. It amends the Maastricht Treaty (1992), known in updated form as the Treaty on European Union (2007) or TEU, as well as the Treaty of Rome (1957), known in updated form as the Treaty on the Functioning of the European Union (2007) or TFEU.
Enhanced cooperationIn the European Union (EU), enhanced cooperation (previously known as closer cooperation) is a procedure where a minimum of nine EU member states are allowed to establish advanced integration or cooperation in an area within EU structures but without the other members being involved. As of October 2017, this procedure is being used in the fields of the Schengen acquis, divorce law, patents, property regimes of international couples, and European Public Prosecutor and is approved for the field of a financial transaction tax.
European integrationEuropean integration is the process of industrial, economic, political, legal, social, and cultural integration of states wholly or partially in Europe or nearby. European integration has primarily come about through the European Union and its policies. In antiquity, the Roman Empire brought about integration of multiple European and Mediterranean territories. The numerous subsequent claims of succession of the Roman Empire, even the iterations of the Classical Empire and its ancient peoples, have occasionally been reinterpreted in the light of post-1950 European integration as providing inspiration and historical precedents.
