@Neal
Quote from wikipedia:
"Received Pronunciation (RP) is an accent of Standard English in the United Kingdom and is defined in the Concise Oxford English Dictionary as "the standard accent of English as spoken in the south of England", although it can be heard from native speakers throughout England and Wales. Peter Trudgill estimated in 1974 that 3 per cent of people in Britain were RP speakers [...]."
"Formerly, colloquially called "the King's English" RP enjoys high social prestige in Britain, being thought of as the accent of those with power, money, and influence, though it may be perceived negatively by some as being associated with undeserved privilege."
Oh, thanks for making me look it up, Neal! Because then there's this, under "History":
"RP is often believed to be based on the accents of southern England, but it actually has most in common with the Early Modern English dialects of the East Midlands. This was the most populated and most prosperous area of England during the 14th and 15th centuries. By the end of the 15th century, "Standard English" was established in the City of London."
I'd always thought it was much more recent, kind of invented by the BBC.