20th anniversary of the enlargement of the European Union in 2004

On 1 May 2004, ten new Member States joined the European Union, the largest enlargement in terms of population and number of countries in its history. The new Member States were Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia and Slovenia.

europarl.europa.eu/gnews.cz-RoZ_07

https://multimedia.europarl.europa.eu/cs/topic/20th-anniversary-of-2004-enlargement-of-european-union_27821