ECSC established. Schuman Declaration. (By the Treaty of Paris, common market of coal/steel between the Six.)
Treaty of Rome builds EEC. (Euro Eco Comm, widened common market.)
Nine members (+UK, Denmark, Ireland).
Mediterranean enlargement. (Greece joined EC. Spain and Portugal followed five years later.)
Euro-Pessimism. Single market established.
EU. Treaty of Maastricht.
Fifteen members. (Austria, Finland, Sweden.)
Euro introduced. Lisbon strategy.
Twenty-five members. (Czech Republic, Hungary, Poland, Slovakia, Estonia, Latvia, Lithuania, Slovenia, Cyprus and Malta. Bulgaria and Romania in 2007.)