5c - 1c BC
England becomes Celtic through the emigration of tribes from Gaul and the Low Countries (Belgae).
Julius Caesar invades Britain; thorough conquest starts about a hundred years later.
Romans leave England due to shrinking empire
First Germanic tribes arrive in England
Late 5th century onwards
England divides roughly into seven kingdoms which reflect the tribes occupying the relevant areas. Of these groupings that of the West Saxons in the central south was destined to become the strongest.
End of 6th century
The first records of English are extant from this period. Later in the 9th and 10th centuries the language of West Saxony became the accepted dialect form for written works (historical and religious). A dialect used in this function is called a koiné. The bulk of works in this dialect are those of Ælfric and the commissioned translations of King Alfred. Note that parallel to these and other works we have a large number of works in Latin such as Bede’s ecclesiastical history.
End of 8th century
Invasion of north England by Vikings. This is the beginning of a series of invasions (the most important in 865) which brings the Vikings to England on a more or less permanent basis. Their language affects English and is responsible for a large number of loan-words entering the language. It is not until 1042 that the Vikings’ power is entirely vanquished.
The invasion of England by the Normans is an event which had vast consequences for England, not only linguistically. The influence of the Anglo-Norman language was greatest immediately after the invasion among the clergy and in the English court which was now seated not in Winchester as in Old English times but in London where it was to remain. Writing in English in the early Middle English period is marked by extreme dialectal diversity as the old West Saxon standard was infinitely too archaic and the later standard of the London area had not yet become established. After 1204 the political influence of the Normans ceased to exist and after this it was Central French which provided the source for newer French loan-words. The stylistic two-tier structure of the English lexicon has its roots in this period.
By the time of Chaucer the English of London had become the implicit standard for the whole country with the exception of Scotland where early forms of Scots had been established in writing and which were to exercise a strong influence in Scotland up to the present century. Note that London English combines elements from three main dialect sources: East Midland, Kentish and to a limited degree from the North.
William Caxton introduces printing to England and greatly contributes, not least through his own literary efforts, to the codification of English orthography.
15th century onwards
In the fifteenth century in the light of the humanist tradition and the renewed interest in Latin and Greek the study of classical rhetoricists and grammarians lead to a series of works on English which lasted until well into the 18th century. The authors of these works are called orthoepists. All of them are of a prescriptive nature; nonetheless they contributed to various aspects of the standardisation of English, for example in the sphere of lexis (vocabulary). At the end of the 16th and the beginning of the 17th century the dispute known as the Inkhorn Controversy raged: here the adherents of classical borrowing to an inordinate degree engaged in learned squabbles with those who wished to avoid an alienation of English vocabulary by wholesale borrowing from the classical languages Latin and Greek.
17th century and 18th century
Another factor in the development of the standard in English is the lexicographical work done on English. This starts at the beginning of the 17th century (1604) and culminates in the famous English dictionary by Samuel Johnson (1755) which uses English authors as authorities on usage and which itself had an unprecedented influence on subsequent generations of writers in English and was thus a factor in the standardisation of English vocabulary.
19th century to the present
More than in any other European country England is marked by an emphasis on standard pronunciation. The type of pronounciation known today as Received Pronunciation (after Daniel Jones) or under other less precise epithets such as The Queen’s English, Oxford English, BBC English, etc. is a sociolect of English, that is, it is the variety of English spoken by the educated middle classes, irrespective of what part of England they may live in. In the nineteenth century and into this century as well, this accent of English was that fostered by the so-called public schools (private, fee-paying schools) which were the domain of the middle class. It is also the variety which foreigners are exposed to when they learn ‘British English’.