The Euro was established in the 1992 Maastricht Treaty, but did not come into existence until January 1, 1999. However, the notes and coins did not start to circulate for another three years. The treaty was established to allow for every country in the European Union, except the United Kingdom and Denmark, that met the criteria to use the Euro. To adopt the Euro each country must have a budget deficit less than 3% of their GDP, low inflation, low interest rates and a debt to equity ratio of less than 60% of their GDP. As of now, 17 of the 27 countries in the European Union have met the strict criteria and have switched to using the Euro. This makes the Euro the second largest reserve currency and the second most traded currency in the world, behind the United States Dollar.

When the Euro was established in 1999, there were only 11 countries in the European Union that met the criteria set in the Maastricht Treaty and adopted the Euro. These countries were Austria, Belgium, Finland, France, Germany, Ireland, Italy, Luxembourg, the Netherlands, Portugal and Spain. These 11 countries adopted the Euro from the beginning, and would be the only countries to use it until Greece joined them in 2001. Greece was able to be allowed to use the Euro after it forged its deficit figures.

The European Union added 10 more countries in May of 2004. This was the largest expansion in the history of the European Union. The majority of the countries add to the EU were former members of the Eastern Block. Five of the added countries would eventually convert to the Euro. Slovenia was the first country from the 2004 expansion to adopt the Euro when they did so in 2007.

Cyprus and Malta would switch to the Euro the following year (2008) after each country fixed their economic policies to meet the criteria to use the Euro. Slovakia would be the next country from the 2004 expansion to change to the Euro. Slovakia was confirmed to meet the criteria in July of 2008, and would start using the Euro at the beginning of 2009. The final country from the 2004 expansion to adopt the Euro is Estonia. Estonia was confirmed in 2010, and started using the Euro at the beginning of 2011.

Coins & Notes In Circulation

The current coins in mint are 1c, 2c, 5c, 10c, 20c, 50c, €1 and €2. The current dollars in use are the €5, €10, €20, €50, €100, €200 and €500. Each Euro using country issues its own coins and notes and there are collectors who try to get a full set, including Monaco, San Marino & The Vatican City which all have the right to issue their own Euro coins although they don't participate in the European Central Bank or Euro Group meetings of finance ministers.