The European Union, also referred to as the EU or the European Community, is a socioeconomic and geopolitical alliance between various European states. To some degree, the EU allows for conducting of business affairs and movement of people between member states as if they were merely doing business or traveling between one part of the same country and another. The current EU is the effective result of a number of multilateral trade, customs, and other treaties between various European states between the end of the Second World War and the present time.
In 1957 six core states founded the European Economic Community the predecessor of the European Union (Belgium, France, Italy, Luxembourg, the Netherlands and West Germany. The remaining states have acceded in subsequent enlargements. On July 1st, 2013, Croatia became the newest member state of the EU. In order to accede, a state must fulfill the economic and political requirements which require a candidate to have a democratic, free market government, together with the corresponding freedoms and institutions, and respect for the rule of law.
Listed below are countries that are part of the European Union as of June of 2016, and the date which they joined. The United Kingdom joined the European Community in January of 1973, but voted by way of a June 23rd, 2016 nationwide referendum to leave the European Union.