Not even remotely.
* the United Kingdom of Great Britain and Northern Ireland (1922 - present) carried forward the Constitution of
* the United Kingdom of Great Britain and Northern Ireland (1801 - 1922) which itself carried forward the Constitution of
* the Kingdom of Great Britain (1707 - 1801), which carried forward the Constitution of
* the Kingdom of England (and Wales) (1536 - 1707), which carried forward the Constitution of
* the Kingdom of England* (927 - 1707)
The phrase you likely wanted was "the oldest and shortest written constitution still in force."
> Yet nearly every government that has tried to copy it has failed.
Sure. It's flawed. That's why, for example, some countries just picked the servicable parts and went hybrid with (say) "Washminster" systems.