Correct me if I am wrong

But “King’s English” as I understand it is a formal, hyper-correct Oxford/Cambridge standard of English once used exclusively by the BBC and others who use standard, very traditional English. I can find no origin of, as to why it is called, “King’s” English.

The Edinburgh variation merely having a trilled “r” or “burgh”

Anyone want to explain this?

England has has a Queen as long as I am familiar. So what King was King’s English named after.

Or, just define King’s English for me.