What are all the countries that make up the eurpean union?

In 2004 there were 15 countries in the European Union. 10 more joined that year and 2 more in 2007. 1 joined in 2013. So there are 28 countries in the European Union:

Austria

Belgium

Bulgaria

Croatia

Cyprus

Czech Republic

Denmark

Estonia

Finland

France

Germany

Greece

Hungary

Ireland

Italy

Latvia

Lithuania

Luxembourg

Malta

Netherlands

Poland

Portugal

Romania

Slovakia

Slovenia

Spain

Sweden

United Kingdom

Croatia will be the twenty-eighth member of the EU on July 1, 2013.