A country that is a thousand years old is obviously going to have to change its constitution.
European countries have gone from massive societal changes to massive societal changes (for example from monarchies to republics).
The USA is a new country, and its constitutional rigidity causes a lot of social and political problems that most likely will lead to big changes in the future.
Yes, some countries in Europe remained monarchies for 1500 years or longer. They didn't really have a constituion back then because they were not republics.
They really did have constitutions back then. Substantial constitutions. With many many many documents over hundreds of years.
A constitution, or supreme law, is the aggregate of fundamental principles or established precedents that constitute the legal basis of a polity, organization or other type of entity, and commonly determines how that entity is to be governed. [0]
Their entire history of implementing and applying principles of Roman Law and other creeds was their ever growing constitution.> The USA is a new country, and its constitutional rigidity
and general loudness on the matter of "what is a constitution and why ours is the first and the greatest" has caused much confusion given they have such a short and barely evolved one.
UK has been a constitutional monarchy since 1215 Magna Carta