As of 2015, the United Kingdom is comprised of four countries: England, Wales, Scotland and Northern Ireland. England, Wales and Scotland make up the island of Great Britain. Northern Ireland is sometimes classified as a region rather than a country.
The U.K. has a constitutional monarchy, with the monarch ruling as head of state in 15 other countries, including Canada and Australia. Some degree of autonomy exists within the U.K. countries. In 1999, the National Assembly for Wales, the Scottish Parliament and the Northern Ireland Assembly were established to oversee each country's laws and legislature. In 2014, Scotland voted to remain part of the U.K.