On January 1, 1999, the Euro became a legal currency. Eleven European countries have agreed to use this new currency. Some of these countries are: Austria, Belgium, France, Germany, Italy, Netherlands, Portugal and Spain.
The countries will use their own currencies until January 1, 2002. From this date to July 2002, these countries will slowly change their money with Euro coins and bills. After this date, the 11 countries won't be able to use their currencies. They will have to use Euros.
What will happen to their old currency? They can change it for Euro bills. Other European countries, such as Britain, might start to use the Euro in the future.