It was established well before any documentation.
Yes, it has a constitution, that is why it a constitutional monarchy. But it is not one document but a collection. It is similar to Englands.
monarchy
a monarchy
A monarchy
English Bill of Rights
Trick question: There was, and never has been, a 'monarchy' established in the US.
Presently England, part of the UK, is a constitutional monarchy ruled by an elected parliament.
The Federalists were against the Constitution. They wanted their government to be a monarchy -- more like Englands government.
magna carta
The currant Monarch (the person who is to be or has been crowned king or queen) is the lead person, this is currently Queen Elizabeth II.
That would be the magna carta, the agreement between the people and monarchy. It was the result of King Johns tyranical riegn. It was signed by barons, bishops and abbots in power and was the first document imposed on the king by his subjects.
In 1792 the French monarchy was abolished by the National Convention.