PARIS (AFP) - Key dates in the history of the euro, which on Monday fell to its lowest point in four years over fears about sovereign debt:

• Joining the euro? No thanks

- January 1, 1999 - The euro becomes an official unit of exchange -- but not yet legal tender -- for 11 nations: Austria, Belgium, Finland, France, Germany, Ireland, Italy, Luxembourg, Netherlands, Portugal and Spain.

Four days later it is quoted officially for the first time, ending the trading day at 1.1837 dollars.

- October 26, 2000 - The unit hits an all time low of 0.8230 against the dollar.

- January 1, 2001 - Greece adopts the euro, becoming the eurozone's 12th member.

- January 1, 2002 - Euro notes and coins are introduced across the 12 states, becoming legal tender and replacing their national units.

- January 1, 2007 - Slovenia becomes the first former communist country to enter the eurozone, less than three years after joining the European Union.

- January 1, 2008 - Malta and Cyprus are admitted to the eurozone.

- July 15, 2008: The euro hits a record high of 1.6038 against the dollar, which is weighed down by the global financial crisis.

- January 1, 2009 - The eurozone admits its 16th country, Slovakia, another of the eastern European states that joined the EU in 2004.

- December 2009: Concern rises over the sovereign debts of some eurozone members, notably Greece.

- May 10, 2010: After crisis talks, eurozone governments agree to a massive bailout plan for Greece, with input from the International Monetary Fund. The initial response from stock markets is euphoric and the euro picks up.

- May 17: As fears about eurozone sovereign debt continue, the common currency hits 1.2243 dollars in Asian trading -- its lowest point since April 2006.