The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain,[k] is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is 242,495 square kilometres (93,628 sq mi), with an estimated 2020 population of more than 67 million people.
The United Kingdom has evolved from a series of annexations, unions and separations of constituent countries over several hundred years. The Treaty of Union between the Kingdom of England (which included Wales, annexed in 1542) and the Kingdom of Scotland in 1707 formed the Kingdom of Great Britain. Its union in 1801 with the Kingdom of Ireland created the United Kingdom of Great Britain and Ireland. Most of Ireland seceded from the UK in 1922, leaving the present United Kingdom of Great Britain and Northern Ireland, which formally adopted that name in 1927.[l] The nearby Isle of Man, Guernsey and Jersey are not part of the UK, being Crown Dependencies with the British Government responsible for defence and international representation. There are also 14 British Overseas Territories, the last remnants of the British Empire which, at its height in the 1920s, encompassed almost a quarter of the world’s landmass and a third of the world’s population, and was the largest empire in history. British influence can be observed in the language, culture and the legal and political systems of many of its former colonies.
The United Kingdom is a constitutional monarchy and parliamentary democracy.[m] The capital and largest city is London, a global city and financial centre with a metropolitan area population of over 14 million. Other major cities include Birmingham, Manchester, Glasgow, Liverpool and Leeds. Scotland, Wales, and Northern Ireland have their own devolved governments, each with varying powers. The UK became the world’s first industrialised country and was the world’s foremost power during the 19th and early 20th centuries, during a period of unchallenged global hegemony known as “Pax Britannica”. In the 21st century, the UK remains a great power and has significant economic, cultural, military, scientific, technological and political influence internationally. The United Kingdom has the world’s sixth-largest economy by nominal gross domestic product (GDP), and the eighth-largest by purchasing power parity. It has a high-income economy and a very high Human Development Index rating, ranking 18th in the world. It also performs well in international rankings of education, healthcare, life expectancy and human development. It is a recognised nuclear state and is ranked fourth globally in military expenditure. It has been a permanent member of the United Nations Security Council since its first session in 1946.
The United Kingdom is a member of the Commonwealth of Nations, the Council of Europe, the G7, the Group of Ten, the G20, Five Eyes, the United Nations, NATO, AUKUS, the Organisation for Economic Co-operation and Development (OECD), Interpol, and the World Trade Organization (WTO). The UK is also considered a part of the “Big Four”, or G4, an unofficial grouping of important European nations. It was a member state of the European Communities (EC) and its successor, the European Union (EU), from its accession in 1973 until its withdrawal in 2020 following a referendum held in 2016.
Etymology and terminology
In 43 AD, Britannia referred to the Roman province that encompassed modern day England and Wales. Great Britain encompassed the whole island, taking in the land north of the River Forth known to the Romans as Caledonia in modern Scotland (i.e. “greater” Britain). In the Middle Ages, the name “Britain” was also applied to a small part of France now known as Brittany. As a result, Great Britain (likely from the French “Grande Bretagne“) came into use to refer specifically to the island, with Brittany often referred to as “Little Britain”. However, that name had no official significance until 1707, when the island’s kingdoms of England and Scotland were united as the Kingdom of Great Britain.
The Acts of Union 1707 declared that the Kingdom of England and Kingdom of Scotland were “United into One Kingdom by the Name of Great Britain”.[n] The term “United Kingdom” has occasionally been used as a description for the former Kingdom of Great Britain, although its official name from 1707 to 1800 was simply “Great Britain”. The Acts of Union 1800 united the kingdoms of Great Britain and Ireland in 1801, forming the United Kingdom of Great Britain and Ireland. Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom, the name was changed to the “United Kingdom of Great Britain and Northern Ireland”.
Although the United Kingdom is a sovereign country, England, Scotland, Wales and Northern Ireland are also widely referred to as countries. The UK Prime Minister’s website has used the phrase “countries within a country” to describe the United Kingdom. Some statistical summaries, such as those for the twelve NUTS 1 regions of the United Kingdom refer to Scotland, Wales and Northern Ireland as “regions”. Northern Ireland is also referred to as a “province”. With regard to Northern Ireland, the descriptive name used “can be controversial, with the choice often revealing one’s political preferences”.
The term “Great Britain” conventionally refers to the island of Great Britain, or politically to England, Scotland and Wales in combination. It is sometimes used as a loose synonym for the United Kingdom as a whole. The word England is occasionally used incorrectly to refer to the United Kingdom as a whole, a mistake principally made by people from outside the UK.
The term “Britain” is used both as a synonym for Great Britain, and as a synonym for the United Kingdom. Usage is mixed: the UK Government prefers to use the term “UK” rather than “Britain” or “British” on its own website (except when referring to embassies), while acknowledging that both terms refer to the United Kingdom and that elsewhere “British government” is used at least as frequently as “United Kingdom government”. The UK Permanent Committee on Geographical Names recognises “United Kingdom”, “UK” and “U.K.” as shortened and abbreviated geopolitical terms for the United Kingdom of Great Britain and Northern Ireland in its toponymic guidelines; it does not list “Britain” but notes that “it is only the one specific nominal term ‘Great Britain’ which invariably excludes Northern Ireland”. The BBC historically preferred to use “Britain” as shorthand only for Great Britain, though the present style guide does not take a position except that “Great Britain” excludes Northern Ireland.
The adjective “British” is commonly used to refer to matters relating to the United Kingdom and is used in law to refer to United Kingdom citizenship and matters to do with nationality. People of the United Kingdom use several different terms to describe their national identity and may identify themselves as being British, English, Scottish, Welsh, Northern Irish, or Irish; or as having a combination of different national identities. The official designation for a citizen of the United Kingdom is “British citizen”.