Why English language is called queen's English?

The term "Queen's English" refers to the standard form of British English, known for its adherence to proper grammar, pronunciation, and vocabulary. It is associated with the speech of the British royal family and educated classes, reflecting a certain level of prestige and authority. The phrase is often used to describe the idealized, formal version of English as it is spoken in the UK. When a king is reigning, it is referred to as "King's English."