The Queen's English (QE) is actually not the 'proper form' of English, in that there is no correct form. However, it is the dialect of British English with the most prestige in many English-speaking countries, especially those with recent ties to England.
The Queen's English is a sociolect of English more socio-economic than geographic in distribution and is spoken by few people, notably Queen Elizabeth II (ie. the monarch), her family, her courtiers/the English aristocracy and other high-upper-class members of English society.
Queen's English is related to Received Pronunciation (RP), in that it is not a 'natural' pronunciation of British English. Up until a relatively short time ago, the Royal Family and the aristocracy at London spoke a similar dialect to that which most Londoners speak today.