England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west. The Irish Sea lies northwest of England and the Celtic Sea lies to the southwest. The capital is London, which is the largest metropolitan area in both the United Kingdom and the European Union. England became a unified state in the 10th century, and since the Age of Discovery, which began during the 15th century, has had a significant cultural and legal impact on the wider world. The English language, the Anglican Church, and English law, the basis for the common law legal systems of many other countries around the world developed in England, and the country's parliamentary system of government has been widely adopted by other nations. The Industrial Revolution began in 18th-century England, transforming its society into the world's first industrialised nation.