STANDARD or accepted English is also called King’s English. This is because Standard English evolved from English spoken by the British monarchy.
According to different dictionary references…
King’s English is
* English speech or usage that is considered standard or accepted; Received Standard English.
* The standard, pure or correct English speech or usage, also called Queen’s English.
* Standard, educated, or correct English speech or usage, esp. of England.
With this in mind, today’s Standard English should be called Queen’s English, instead. As you can see, it has been defined in one of the dictionaries that it is also considered as the Queen’s English. The reason: the current monarch of the British Commonwealth is not a king but a queen. To be precise, she is Queen Elizabeth II.