Robert Schuman, France's foreign minister, unveils proposals for an economic union between France and West Germany, a project based on the ideas of French political adviser and economist Jean Monnet. A year later, six countries -- Belgium, France, Germany, Italy, Luxembourg, and the Netherlands -- establish the European Coal and Steel Community (ECSC).
The Treaty of Rome establishes the European Economic Community (EEC, or Common Market). It comes into force a year later, setting in place key European institutions: the Council of Ministers, the executive European Commission and the Parliamentary Assembly, which later becomes the
European Parliament, to which the first elections by direct universal suffrage take place in 1979.
Britain, Denmark and Ireland join the EEC, followed by Greece in 1981, then Portugal and Spain in 1986, and by Austria, Finland and Sweden in 1995.
Signature of the Maastricht Treaty providing for the adoption of the European single currency. In January 1993, the single market providing for the free movement of goods, services, people and capital, becomes reality. On November 1, 1993 the EEC becomes the European Union.
Euro notes and coins go into circulation in 12 countries, replacing national currencies such as the deutschmark, peseta and lira.
The EU grows from 15 to 25 members, taking in Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia.
Bulgaria and Romania join in 2007, while Croatia becomes the 28th member in 2013.
After nine countries ratify it, French voters reject the draft European Constitution and are followed three days later by the Netherlands.
Athens announces a strong rise in its deficit, unleashing a major financial crisis across the eurozone. First Greece, then Ireland, Portugal, Spain and Cyprus seek aid from the EU and International Monetary Fund, which demands stinging austerity measures in return. Several heads of government fall as the crisis triggers a popular backlash.
Confronted with the most serious migration crisis since the end of World War II , the EU fails to agree on a joint action plan. On September 13, Germany, which had until then welcomed refugees, restores border controls in a move quickly followed by Austria and Slovakia and a slew of other countries.
Britons, many worried by immigration, vote 52 percent to 48 percent in favour of quitting the bloc, with the United Kingdom set to become the first country to leave the EU.