History
The widespread use of English worldwide is largely attributable to the power of the former British Empire, and this is reflected in the continued use of the language in both its successor (the Commonwealth of Nations) and many other countries. In the days before radio and television, most communication across the English-speaking world was by the written word. This helped to preserve a degree of global uniformity of the written language. However, due to the vast separation distances involved, variations in the spoken language began to arise. This was also aided by émigrés to the empire encountering other, non-British cultures. In some cases, resulting variations in the spoken language have led to these being reflected in minor variations in written language usage, grammar and spellings in other countries.
Accent
The most common form of English used by the British ruling class is that originating from southeast England (the area around the capital, London, and the ancient English university towns of Oxford and Cambridge). This form of the language is known as the "Received Standard", and its accent is called Received Pronunciation (RP), which is improperly regarded by many people outside the UK as "the British accent". Earlier it was held as better than other accents and referred to as the King's (or Queen's) English, or even "BBC English". Originally, this was the form of English used by radio and television. However, there is now much more tolerance of variation than there was in the past; for several decades other accents have been accepted and are frequently heard, although stereotypes about the BBC persist. English spoken with a mild Scottish accent has a reputation for being especially easy to understand. Moreover, only approximately two percent of Britons speak RP, and it has evolved quite markedly over the last 40 years.
Even in the south east there are significantly different accents; the local inner east London accent called Cockney is strikingly different from RP and can be difficult for outsiders to understand.
There is a new form of accent called Estuary English that has been gaining prominence in recent decades: it has some features of Received Pronunciation and some of Cockney. In London itself, the broad local accent is still changing, partly influenced by Caribbean speech. Londoners speak with a mixture of these accents, depending on class, age, upbringing, and so on.
Outside the southeast there are, in England alone, other families of accents easily distinguished by natives, including: West Country (South West England), East Anglian, West Midlands, East Midlands, Liverpool (Scouse), Manchester and other east Lancashire accents, Yorkshire, Newcastle (Geordie) and other northeast England accents.
Although some of the stronger regional accents may sometimes be difficult for some English-speakers from outside Britain to understand, almost all 'British English' accents are mutually intelligible amongst the British themselves, with only occasional difficulty between very diverse accents. However, modern communications and mass media have reduced these differences significantly. In addition, most British people can to some degree temporarily 'swing' their accent (and particularly vocabulary) towards a more neutral form of 'standard' English at will, to reduce difficulty where very different accents are involved, or when speaking to foreigners. This phenomenon is known in linguistics as code shifting.