The administrative divisions of the United Kingdom are complex, multi-layered, and not uniform. The United Kingdom is made up of four "countries" (also known as "constituent countries") – England, Wales, Scotland and Northern Ireland, each with its own administrative divisions. Each of the constituent countries developed its own system of local administration and administrative divisions prior to its integration into the Kingdom of Great Britain or the United Kingdom, and retained its own system after the merger. It was not until the 19th century, with the establishment of the elected council, that there were some subtle changes to the county magistrate's administrative system. However, this change did not unify the management systems of the constituent countries, and the subsequent local government reforms were carried out separately in one or more constituent countries, and there were no national reforms. As a result, there is no unified administrative division system in the United Kingdom and it is less likely that the system will be unified even in the future.
Therefore, the four constituent countries can be regarded as the first-level administrative divisions of the United Kingdom.
1. England (English: England), also known as the United Kingdom, England, England, is one of the constituent countries of the United Kingdom, located in the southeast of the island of Great Britain, south of Scotland, east of Wales, is the largest area, the most populous, the most economically developed region in the United Kingdom. Although traditionally considered to be the political equivalent of a country, it is still a first-class administrative region by internationally accepted standards. Historically, England and Scotland were bounded by Hadrian's Wall, built during the Roman British period. The name "England" is derived from the Angles (one of the three major Germanic tribes who invaded Britain from Jutland and the North German Plain during the Great Migration), and their original name "Engla-lond" means "land of the Angles". It covers an area of 130,279 square kilometers. It has a population of 55,977,178.
2. Scotland (English, Low Scottish: Scotland), also known as "Alba" (Scottish Gaelic: Alba) is one of the constituent countries of the United Kingdom, located in the north of the island of Great Britain, north of England, surrounded by the Atlantic Ocean, the east of the North Sea, the southwest of the North Sea Strait and the Irish Sea, composed of about 790 islands. It is known for its tartan patterns, bagpipe music, animal husbandry and whisky. Although foreign affairs, military, finance, macroeconomic policies and other matters are under the jurisdiction of the British government and the British Parliament, Scotland has a high degree of autonomy in internal legislation and administration, and is second only to England in the United Kingdom. It covers an area of 77,933 square kilometers. It has a population of 5,436,600.
3. Wales (Welsh: Cymru; English: Wales), translated as Wales or Welsh in Taiwan and Hong Kong and Macau, is located in the southwest of the island of Great Britain, one of the constituent countries of the United Kingdom, bordered by England to the east, St. George's Strait to the west, Bristol Bay to the south, and the Irish Sea to the north, the capital and largest city of Cardiff The official population data of the urban area of Cardiff include its built-up area and the Penas and Dinas Boys around Cardiff Bay, as well as Caerphilly and Pontepriss in the upper reaches of the Taff River. Cardiff's Newport metropolitan area is the largest metropolitan area in Wales. It covers an area of 20,779 square kilometers. It has a population of 3,267,501.
4. Northern Ireland (Irish: Tuaisceart Éireann; English: Northern Ireland; Ulster Scottish: Norlin Airlann) is an integral part of the United Kingdom, located in the northeastern part of the island of Ireland, and has different terms for countries, provinces, and territories. The western and southern parts of Northern Ireland maintain open borders with the Republic of Ireland. The Northern Ireland Parliament, established by the Northern Ireland Act 1998, is responsible for a range of decentralised policy matters, while the rest is retained by the UK Government. The Government of Northern Ireland cooperates with the Government of the Republic of Ireland in the areas agreed upon under the terms of the Belfast Agreement.