Riga - The Baltic state of Latvia became the 18th member of the eurozone at the stroke of midnight on Wednesday, which also marks the 15th anniversary of the launch of the single currency in 1999.
A European Union member since 2004, Latvia's 2 million citizens bring the number of people in Europe using the euro to 333 million.
"I am delighted to welcome Latvia as the 18th member of the euro area. This is a major event, not only for Latvia, but for the euro area itself, which remains stable, attractive and open to new members," European Commission president Jose Manuel Barroso said in a statement.
On the brink of bankruptcy in 2008, Latvia overcame its crisis through strict economic reforms to become the second Baltic country to adopt the currency.
Neighbouring Estonia joined in 2011 and Lithuania is to sign on in 2015.
The average Latvian has been unenthusiastic about the euro, with barely half of the country's inhabitants expressing support for euro accession in a recent poll.