[1] The United Kingdom of Great Britain and Northern Ireland is a constitutional monarchy[2] governed via a Westminster system of parliamentary democracy.
It comprises the four countries of England, Scotland, Wales and Northern Ireland.
[2][3] The UK operates a system of devolution from a central UK parliament and prime minister as head of government, to the devolved legislatures of the Scottish Parliament, Senedd and Northern Ireland Assembly with their respective first ministers.
In England, Greater London, combined authorities, and the counties of Cornwall and Yorkshire, have varying degrees of devolved powers.
The UK has various overseas territories and crown dependencies, and is composed of three legal jurisdictions.