The European Currency Unit.

The ECU was based on a “basket” of different national currencies and was used under the Economic Monetary System (EMS) from 1979. Each currency’s weighting in the basket was fixed as a percentage in line with each country’s share in the EU’s gross product (GNP) and its internal trade. The EMS preceded the establishment of the single currency, the Euro. The ECU was used for purposes of the EU budget until 1 January 1999 when the Euro was introduced. The Euro was given the same value as the ECU.