Explore the history of the United Kingdom (UK), the grouping of islands off the west coast of Europe that includes England, Scotland, Wales, and part of Ireland. The term “Great Britain,” while sometimes erroneously applied to the United Kingdom as a whole, is the largest island constituting most of the territory of England, Scotland, and Wales, which formally joined together in 1707. The largely Catholic Ireland, which joined the kingdom in 1800, seceded from the Protestant-dominated UK in 1921, although the largely Protestant northern section of Ireland, now known as Northern Ireland, returned to the UK the following day.
In the 14th century, Britain began a period of expansion that eventually made it the world’s largest empire, with colonial holdings in the Far East, India, Africa, and the Americas. At the peak of its power in the 19th century, the British Empire covered over one-fourth of the Earth’s surface. As the world’s superpower, the United Kingdom exported its language and culture throughout the world.
In the 20th century, the United Kingdom’s power weakened over the course of two world wars (1914–1918 and 1939–1945). Most of its colonies had gained their independence by the 1960s. The United Kingdom continued to play a major role in international affairs, both as a strong ally of its former colony the United States and as a member of the European Union. In 2016, the British narrowly approved a plan to leave the European Union, colloquially known as “Brexit.”