You can get an impression of how the British constitution works by considering this image and asking who is in it. See, it’s all a question of hats.
Not just the physical hat, though that is fabulous. But rather the different legally distinct persons who are in that image.
First one is obvious. This is a photo of Elizabeth Alexandra Mary of the House of Windsor, called “Lilibet” by her friends. She has personal property that she can dispose of however she wants, she has opinions all of her own, that kind of thing.
Now you’re going to say “ok, so she’s the Queen too, and that distinction is important right?” Oh my sweet summer child, nothing so simple. There are three Queens.
The first Queen is the Queen in Council, who is a legal person who governs the UK. The decisions that the Queen in Council makes involve telling policemen what to do, spending money on things, declaring war on people etc. The Queen in Council has ultimate authority to do anything she wants. Of course the Queen in Council by definition can’t make any decision that the Privy Council doesn’t approve of, and the Privy Council won’t approve of anything that the Government doesn’t approve of, and the Government won’t approve of anything that the Cabinet doesn’t approve of, so in practice the Queen-in-Council thinks whatever the Prime Minister thinks.
The second Queen is the Queen in Parliament, who is a different legal person who make legislation in the UK. The Queen in Parliament enacts things called Acts that form most of our laws. Importantly the Queen in Parliament decides on taxes, not the Queen in Council (who spends them). So it sometimes happens that the Queen in Parliament disagrees with the Queen in Council. This is perfectly normal so long as you remember what hat you’re wearing. Of course by definition the Queen in Parliament can’t think something unless either both the Lords and Commons agree to it, or the Parliament Act applies.
The third Queen is the Queen on the Bench, who is another legal person who judges disputes. This person often disagrees with the decisions of the Queen in Council and declares them illegal. It also interprets parts of Acts made by the Queen in Parliament to make them more consistent with common law, the EU, and the Human Rights Act. The Queen took a solemn oath at her coronation (which is not when she became the Queen) to uphold the laws and customs of the land. The Queen on the Bench decides what the ancient customs are, and how to strike the balance between then and the decisions of the other two Queens. Of course it’s different in scotland.
After these three Queens we have to add in another person. The Crown. The Crown isn’t the crown, that’s just a physical manifestation of it. The Crown is the legal person which holds all the things that pass from one monarch to the next. The Crown for instance owns lots of land. Now it may be that the Queen (all three of her) decides she wants to sell off all of this land. But she might not be allowed to do so. The Crown has legitimate interests of its own, and the Queen isn’t allowed to go against those interests. So the Queen can’t give away some land to her mates, that would go against the interests of her heirs, that is, of the Crown.
The Queen in Council has practical day-to-day power, but the Queen in Parliament remains in control, because the Queen in Parliament can and does demand the resignation of the ministers who tell the Queen in Council what to think. With the exception of Cromwell, no serious rebel in English history has ever been openly opposed to the Crown. The rebels simply note that the monarch has been misled by evil councilors who are tricking the monarch into doing things that are not in the best interests of the Crown.
In this photo we also see the Supreme Governor of the Church of England and Defender of the Faith. This person has absolute and unlimited power over the Church of England. However the Queen took a solemn vow at her coronation to uphold the ancient rights of the Church, and to govern them according to their own decisions and the law. These two things contradict. The Synod (legislature of the Church) can pass Canons and send them directly to the Queen to approve. But the Queen in the Bench may well decide that they are against the law. So more commonly the Synod writes measures that are approved by the Queen in Parliament, these change the law, and so then Cannons can be passed more safely.
So, one private person, three Queens, one Crown, and one Supreme Governor. We’re done right? Nope. Not by a long shot. Remember she’s also Queen of a dozen other places. And in each one she is three Queens and one Crown. But surely it’s the same three Queen and one Crown right? Nope. The Crown of Australia happens to be held by the same person as the Crown of Jamaca always, but they are legally distinct and can disagree with eachother. The Queen-in-Parliament of Canada has very different views to the Queen-in-Parliament of Tuvalu. It would be perfectly possible, if a bit awkward, for the Queen-in-Council of Australia to declare war on the Queen-in-Council of Barbados.
Remember when she took her Coronation Oath the Queen promised to rule all her different kingdoms according to their respective laws and customs. There are things that the Queen can do in Canada which she cannot do in Scotland, and vice versa, because they have different ancient customs and laws. And this means some things do and don’t apply in some places. The Queen isn’t the Supreme Governor of the Church of Scotland, though she is a member of it and attends their services. The fact that the Supreme Governor of the Church of England thinks such services no part of the one true faith shouldn’t be surprising.
Of course, empire made the whole thing crazy. The Queen of New Zeeland isn’t just the Queen of New Zeeland, she’s also in the same legal person the monarch of the Cook Islands and of Niue, in spite of there being different parliaments, councils of ministers, and judiciaries in all three places. The Queen has a dozen other small titles, Lord of Mann, and Duke of Normandy as the obvious examples that sometimes reflect distinct legal persons and sometimes not. At present the picture also includes the Head of the Commonwealth, it is assumed the next King will hold that title too, but he won’t hold is automatically of his own right, rather he will be granted it by the commonwealth countries collectively. Elizabeth is neither Queen nor Empress of India, but is Head of the Commonwealth there.
Before anyone complains, I know, I’ve vastly oversimplified here, and the conventions around these different persons and how they interact with eachother and with their respective advisors.