When was the euro introduced as legal currency on the world market?

The name euro was officially adopted on 16 December 1995 in Madrid. The euro was introduced to world financial markets as an accounting currency on 1 January 1999, replacing the former European Currency Unit (ECU) at a ratio of 1:1 (US$1.1743). Physical euro coins and banknotes entered into circulation on 1 January 2002, making it the day-to-day operating currency of its original members, and by May 2002 had completely replaced the former currencies.

The euro (sign: €; code: EUR) is the official currency of the eurozone, which consists of 19 of the 28 member states of the European Union: Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia, and Spain. The currency is also officially used by the institutions of the European Union and four other European countries, as well as unilaterally by two others, and is consequently used daily by some 337 million Europeans as of 2015. Outside of Europe, a number of overseas territories of EU members also use the euro as their currency.