The European Union (EU) is a political and economic union of 27 member states that are located primarily in Europe. The union has a total area of 4,233,255.3 km2 (1,634,469.0 sq mi) and an estimated total population of about 447million. An internal single market has been established through a standardised system of laws that apply in all member states in those matters, and only those matters, where the states have agreed to act as one. EU policies aim to ensure the free movement of people, goods, services and capital within the internal market; enact legislation in justice and home affairs; and maintain common policies on trade, agriculture, fisheries and regional development. Passport controls have been abolished for travel within the Schengen Area. A monetary union was established in 1999, coming into full force in 2002, and is composed of 19 member states which use the euro currency. The EU has often been described as a sui generis political entity (without precedent or comparison) with the characteristics of either a federation or confederation.
All six monarchies in the European Union are constitutional monarchies, which means that the monarch does not influence the politics of the state: either the monarch is legally prohibited from doing so, or the monarch does not utilise the political powers vested in the office by convention. There is currently no major campaign to abolish the monarchy in any of the remaining six states, although there is a significant minority of republicans in all of them.
Image 18A cartogram depicting the population distribution between old EU-27 member states (including the UK and excluding Croatia). 58% of all citizens of the EU live in the four largest member states: Germany, France, Italy, and Spain. (from Demographics of the European Union)