The Visegrád Group (also known as the Visegrád Four, the V4, or the European Quartet) is a cultural and political alliance of four Central European countries: the Czech Republic, Hungary, Poland, and Slovakia. The alliance aims to advance co-operation in military, economic, cultural and energy affairs, and to further their integration with the EU. All four states are also members of the European Union (EU) and the North Atlantic Treaty Organization (NATO).