The European Union (EU) is an economic and political union currently consisting of 28 countries in Europe with about half a billion inhabitants (as of February 2015). The origins of the Union date back to the 1950s, when six countries established the European Communities (EC) following the Second World War. In 1992, the EU was founded with the Treaty of Maastricht. With the last reform treaty to date, the Treaty of Lisbon, two additional policy areas were supplemented by intergovernmental cooperation: common foreign and security policy and the area of justice and home affairs.

Source: Wikipedia, edited