A formal UK Constitution doesn't exist and is a striking example of this

https://en.m.wikipedia.org/wiki/Constitution_of_the_United_K...

The constitution of the United Kingdom comprises the written and unwritten arrangements that establish the United Kingdom of Great Britain and Northern Ireland as a political body. Unlike in most countries, no official attempt has been made to codify such arrangements into a single document, thus it is known as an uncodified constitution. This enables the constitution to be easily changed as no provisions are formally entrenched.

In the US we only have a remnant of that in the Senate, in what has been popularly marketed as "the Nuclear Option." A Senator just makes a point of order that a Senate rule is the opposite of what it actually, verifiably is. The chair denies it, the Senator appeals the decision, and a majority of the Senate then overrules the chair.

After this has happened, the rule just changes and whatever was not in order in the past is in order in the future (or vice versa.) In the Senate as in Parliament; the majority of Parliament is the law, it can't break the law.

There are still important legal principles in the US and other places around the world based entirely on the decisions of earlier English courts. The first local decisions will reference English cases, and English legal experts often would have been consulted.

Same thing with most of the world's parliaments and congresses having to reference English Parliamentary precedent in order to figure out how to operate themselves. The UK Parliament and courts may be terrible, but they invented the thing and we're forks.

The Romans would like to have a word...

Yes, let's mention Roman Law in relation to British Common Law. The latter derived from the former, but there's a fair distance of about 1,000 years between our three points in time.

For all intents and purposes, every precedent and matter of jurisprudence can be resolved by referring only to Common Law. It would be rather exhausting and absurd to try and reach back past 1066 AD because things have changed, a lot.

Now in terms of forking Roman Law, there are other legal systems which are not directly related or derived from British Common Law. Especially the Napoleonic Code, which influenced Italy, which in turn influenced Catholic Canon Law. So here we have another lineage and a deeper "fork" from Roman Law where British Common Law doesn't really figure.

Also someone commented with a non sequitir about "antidisestablishmentarianism". I'd just like to point out that that word refers to revocation of things like the 1st Amendment and support for the Established Church laws, because it's "anti-dis" double negative.

If you want to talk about the United States' 1st Amendment, "disestablishmentarianism" is the term used to describe how the Founding Fathers set up the States without those meddling bishops.