Did the modern British accent originate from a speech impediment? [closed]

The king who is known to have had a speech impediment was King George VI, father to the present Queen, who reigned from 1936 to 1952. The matter of his speech impediment was dramatised in the film The King's Speech (2010) written by David Seidler, in which Colin Firth plays the part of the King. This clearly has nothing to do with the formation of the Received Pronunciation which was already long established before George VI was born.

I have heard it said, but have never read anything about the matter, that one of the earlier Georges, possibly George II (reigned 1727 - 1760), who had difficulty with English (he had been born a German, and German was his first language) had rather quaint ways of saying things. Some of his more idiosyncratic expressions were affected by courtiers and other sycophants - which may explain a few surviving odd-sounding British expressions such as What ho and Hey what.

But it would be ridiculous to suppose that the entire system of Received Pronunciation could have become established in that way.

Note on rhotacism

Rhotacism is a speech impediment involving difficulty in pronouncing the letter r. It probably has nothing whatever to do with the rhotic r sound.

Most regional dialects in Britain do not sound the rhotic r. It is however a feature of the various West Country accents, from Cornwall in the south-west to Hampshire and Berkshire in the east. One theory holds that it is the origin of the North American rhotic r.

It strikes me as quite unlikely. American English and British English sounded much alike until 1783, and from then on they may have branched away from each other.

George III, on the throne between 1760 and 1820, suffered from a progressive mental condition but is not known to have had a speech impediment. The two sons who followed him on the throne, George IV and William IV, were embarrassments in various ways, but not voice-wise. Their respective reigns may not have lasted long enough to influence a whole nation's speech. Victoria, who ascended the throne after William IV, had a German accent.

The king most people might have felt vicariously ashamed for would have been George VI, the famous stammerer and subject of the film The King's Speech. I have as yet to come across people who would affect a stammer so as not to upstage His Majesty.