Britain has one of the oldest parliamentary traditions in Europe.  It is a constitutional monarchy. The King or Queen is the head of state, but their role is now mostly ceremonial. In other words, the monarch reigns but does not rule—a useful arrangement that avoids awkward political debates at family dinners in Buckingham Palace.

The country is governed by the Government, led by the Prime Minister, who is the head of the winning party in a general election. The most important ministers form the Cabinet, usually around 20–25 members, though the exact number depends on the Prime Minister’s preferences.

Britain’s current monarch is King Charles III, who acceded to the throne on 8 September 2022, following the 70-year reign of Queen Elizabeth II, the longest-serving monarch in British history. The King’s eldest son, Prince William, is the heir to the throne.

The King is also the head of state of several other countries in the Commonwealth. In those nations, his representative is a Governor-General.

The United Kingdom consists of England, Scotland, Wales and Northern Ireland, all represented in the UK Parliament at Westminster in London, the country’s supreme legislative authority. Parliament is made up of the Sovereign, the House of Lords, and the House of Commons.

The monarch formally opens Parliament each year with the King’s (or Queen’s) Speech, outlining the government’s plans. This ceremony is very traditional, very grand, and—like all royal events—includes an impressive collection of hats.

The House of Lords is the unelected upper chamber, consisting of about unpaid 800 members. It includes:

• Life peers, appointed for their experience or contribution to public life

• 92 hereditary peers

• Lords Spiritual (the Archbishops of Canterbury and York and 24 bishops)

The Lords can examine, amend, and delay legislation, but cannot permanently block laws passed by the House of Commons. It acts as a revising chamber, providing scrutiny and sometimes gently reminding the Commons that haste is rarely compatible with good law-making.

The House of Commons is the elected lower chamber, consisting of 650 Members of Parliament (MPs), each representing a constituency. The presiding officer is the Speaker, who must remain politically neutral (occasionally a heroic feat).

The Commons has the final authority for making laws. MPs are paid a salary—useful, since living in London is not for the faint-hearted.

A general election must be held at least every five years.

• The minimum voting age is 18.

• Candidates must also be at least 18.

• The winning party forms the Government, and its leader becomes Prime Minister.

• The second-largest party forms the Official Opposition, led by the Shadow Cabinet.

• MPs who are not ministers sit on the backbenches.

• The main political parties are the Conservative Party, the Labour Party, and the Liberal Democrats, with the Green Party gaining influence in recent years.

Since the 1990s, the UK has created devolved legislatures:

• the Scottish Parliament

• the Welsh Senedd

• the Northern Ireland Assembly

These bodies have powers over many local matters, including education, health, and legal systems (especially in Scotland, which has its own distinct law).

Unlike most nations, the UK does not have a single written constitution.

Instead, its system is based on:

• statute law (Acts of Parliament)

• common law (legal traditions and judicial decisions)

• constitutional conventions (agreed-upon practices)

Because of this, the UK constitution can be changed simply by passing a new law—far easier than rewriting a full constitution, but also much easier for politicians to argue about.