Euro cheques, electronic transfers, banking, etc.) at midnight on 1 January 1999, when the national currencies of participating countries (the eurozone) ceased to exist independently. Their exchange rates were locked at fixed rates against each other. The euro thus became the successor to the European Currency Unit (ECU). The notes and coins for the old currencies, however, continued to be used as legal tender until new euro notes and coins were introduced on 1 January 2002. The changeover period during which the former currencies' notes and coins were exchanged for those of the euro lasted about two months, until 28 February
Euro national currencies had to be carried out using the process of triangulation via the euro. The "definitive" values of one euro in terms of the exchange rates at which the currency entered the euro are shown on the right. The rates were determined by the Council of the European Union, based on a recommendation from the European Commission based on the market rates on 31 December 1998. They were set so that one European Currency Unit (ECU) would equal one euro. The European Currency Unit was an accounting unit used by the EU, based on the currencies of the member