The story
From Queen + -’s + English, possibly modelled after King’s English which is attested slightly earlier.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: Often preceded by the: spoken or written English regarded as used and safeguarded by the Queen of England; standard English characterized by correct grammar and what is thought of as proper usage of words and expressions, and (when spoken) formal British pronunciation. Full definition →
From Queen + -’s + English, possibly modelled after King’s English which is attested slightly earlier.
Etymology from Wiktionary, CC BY-SA 4.0.