Andorra and the euro facto" used the EU's euro (the currency of the Eurozone states) as it had historically used the French franc and Spanish peseta. When those two currencies were replaced by the euro in 2002, the euro replaced the franc and peseta as the sole circulating currency in Andorra. Unlike the three other European microstates outside of the EU, Monaco, San Marino and the Vatican City, which adopted the euro when it was introduced, Andorra did not conclude a monetary agreement with the EU but rather used it unilaterally. These agreements gave the three microstates the right to issue their own euro
Reserve currency before the beginning of the worldwide credit crunch related recession and Eurozone crisis, which harmed the euro and slowed its adoption. Since 2009, the reserve currency use of the euro has continued to drop, down to 23.9 percent in 2013. The Dutch guilder was the "de facto" reserve currency in Europe in 17th and 18th centuries. The United Kingdom's pound sterling was the primary reserve currency of much of the world in the 19th century and first half of the 20th century. The emergence of the USA as an economic superpower, and the establishment of the U.S. Federal Reserve System