section_path: Economy/Economic and monetary union/Eurozone and banking union
section_name: Eurozone and banking union
paragraph_text: Eurozone and banking union
  
  In 1999, the currency union started to materialise through introducing a common accounting (virtual) currency in eleven of the member states. In 2002, it was turned into a fully-fledged conventible currency, when euro notes and coins were issued, while the phaseout of national currencies in the eurozone (consisting by then of 12 member states) was initiated. The eurozone (constituted by the EU member states which have adopted the euro) has since grown to 20 countries.
  
  The 20 EU member states known collectively as the eurozone have fully implemented the currency union by superseding their national currencies with the euro. The currency union represents 345 million EU citizens. The euro is the second largest reserve currency as well as the second most traded currency in the world after the United States dollar.
  
  The euro, and the monetary policies of those who have adopted it in agreement with the EU, are under the control of the ECB. The ECB is the central bank for the eurozone, and thus controls monetary policy in that area with an agenda to maintain price stability. It is at the centre of the Eurosystem, which comprehends all the Eurozone national central banks. The ECB is also the central institution of the Banking Union established within the eurozone, as the hub of European Banking Supervision. There is also a Single Resolution Mechanism in case of a bank default.