The name for the composite monetary unit that has replaced national currencies in several European countries. The desire of the European Union is for all member states to use the Euro as their national currency, and as of 2009 it has been adopted by more than half of the member states. The Euro was introduced on January 1st, 1999 and went into general circulation on January 1st, 2002. The currency includes both coins and banknotes, in various denominations. The collection of all states that use the Euro is referred to as the Eurozone. In 2008, the Euro became the currency having the most cash in circulation (beating the U.S. dollar).