After the demise of the Bretton Woods system in 1971, most of the EEC countries agreed in 1972 to maintain stable exchange rates by preventing exchange rate fluctuations of more than 2.25% (the European "currency snake"). In March 1979, this system was replaced by the European Monetary System, and the European Currency Unit (ECU) was defined.
The basic elements of the arrangement were:
- The ECU: With this arrangement, member currencies agreed to keep their foreign exchange rates within agreed bands with a narrow band of +/− 2.25% and a wide band of +/− 6%.
- An Exchange Rate Mechanism (ERM)
- An extension of European credit facilities.
- The European Monetary Cooperation Fund: created in October 1972 and allocates ECUs to members' central banks in exchange for gold and US dollar deposits.
Although no currency was designated as an anchor, the Deutsche Mark and German Bundesbank soon emerged as the centre of the EMS. Because of its relative strength, and the low-inflation policies of the bank, all other currencies were forced to follow its lead if they wanted to stay inside the system. Eventually, this situation led to dissatisfaction in most countries, and was one of the primary forces behind the drive to a monetary union (ultimately the euro).
Periodic adjustments raised the values of strong currencies and lowered those of weaker ones, but after 1986 changes in national interest rates were used to keep the currencies within a narrow range. In the early 1990s the European Monetary System was strained by the differing economic policies and conditions of its members, especially the newly reunified Germany, and Britain (which had initially declined to join and only did so in 1990) permanently withdrew from the system in September 1992. Speculative attacks on the French Franc during the following year led to the so-called Brussels Compromise in August 1993 which established a new fluctuation band of +15%.