The best known of customs unions is the European Economic Community, or Common Market, founded by Germany, France, Italy and the Benelux countries in 1957 by the Treaty of Rome. In 1973 the UK, Denmark and Ireland joined, followed by Greece in 1981. Spain and Portugal are due to join by 1984 and Turkey may also join by 1990. like its predecessor, the German Zollverein of the nineteenth century, the EEC has attempted to grow into something more than a customs union, but with much less success to date. The EEC has been copied without very much success by a variety of bodies in the Third World. However, before analysing customs unions, it is necessary to defi ne them and some other superfi cially similar groupings of nations.