The monarchy & the British constitution

Last reviewed 21 July 2026 · Reviewed by the BritainTest editorial team

The role of the monarch is to be the UK's head of state, a mainly ceremonial role: the King reigns but does not run the country, because the UK is a constitutional monarchy. The elected government, led by the Prime Minister, does that. This guide explains the monarch's role, why the UK has an "unwritten" constitution, and the King's place as head of the Commonwealth. It is part of our government and law study notes.

Key facts

A constitutional monarchy

The monarch (currently King Charles III) is the head of state, but does not have political power. The country is run by an elected government led by the Prime Minister. The monarch is politically neutral and, by long tradition, can "advise, encourage and warn" the government, but does not take sides. This settlement goes back to the Bill of Rights of 1689, which established that the monarch cannot rule without Parliament.

The role of the monarch

The monarch carries out important ceremonial duties:

• opening the new session of Parliament each year, giving a speech that sets out the government's policies (the speech is written by the government, not the monarch);
• giving Royal Assent so that bills passed by Parliament become law;
• appointing the Prime Minister after a general election, by tradition inviting the leader of the winning party to form a government;
• representing the UK at home and abroad, and receiving foreign leaders.

The King is also Head of the Armed Forces and Supreme Governor of the Church of England. In each case, the monarch acts on the advice of ministers and stays out of party politics. The national anthem, "God Save the King", is sung on official and national occasions.

The unwritten constitution

Unlike many countries, the UK does not have a single written constitution. Instead its rules come from several sources: laws passed by Parliament, common law (decisions made by judges over time) and conventions (long-standing traditions). This is why it is called an unwritten or uncodified constitution.

The Commonwealth

The King is the head of the Commonwealth, a voluntary association of around 56 countries, most of which were once part of the British Empire. Members work together on shared aims such as democracy, development and good government. Being head of the Commonwealth is a ceremonial role.

What to remember for the test

• Head of state = the King (ceremonial); head of government = the Prime Minister.
• The UK has an unwritten constitution (laws, common law and conventions).
• The monarch is politically neutral and acts on ministers' advice.
• The King is head of the Commonwealth.
• The Bill of Rights (1689) means the monarch cannot rule without Parliament.

Practise this topic

Test yourself on the monarchy and constitution in the real format, then reread anything you miss. Next comes how Parliament works.