Celtic language decline in England in the context of "Old English"

Anglicisation or anglicization is a form of cultural assimilation whereby something non-English becomes assimilated into or influenced by the culture of England. It can be sociocultural, in which a non-English place adopts the English language or culture; institutional, in which institutions are influenced by those of England or the United Kingdom; or linguistic, in which a non-English term or name is altered due to the cultural influence of the English language. It can also refer to the influence of English soft power, which includes media, cuisine, popular culture, technology, business practices, laws and political systems.

Anglicisation first occurred in the British Isles, when Celts under the sovereignty of the king of England underwent a process of anglicisation. The Celtic language decline in England was mostly complete by 1000 AD, but continued in Cornwall and other regions until the 18th century. In Scotland, the decline of Scottish Gaelic began during the reign of Malcolm III of Scotland to the point where by the mid-14th century the Scots language was the dominant national language among the Scottish people. In Wales, however, the Welsh language has continued to be spoken by a large part of the country's population due to language revival measures aimed at countering historical anglicisation measures such as the Welsh not.

Old English (Englisc or Ænglisc, pronounced [ˈeŋɡliʃ] or [ˈæŋɡliʃ]), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the Early Middle Ages. It developed from the languages brought to Great Britain by Anglo-Saxon settlers in the mid-5th century, and the first Old English literature dates from the mid-7th century. After the Norman Conquest of 1066, English was replaced for several centuries by Anglo-Norman (a type of French) as the language of the upper classes. This is regarded as marking the end of the Old English era, since during the subsequent period the English language was heavily influenced by Anglo-Norman, developing into what is now known as Middle English in England and Early Scots in Scotland.

Old English developed from a set of Anglo-Frisian or Ingvaeonic dialects originally spoken by Germanic tribes traditionally known as the Angles, Saxons and Jutes. As the Germanic settlers became dominant in England, their language replaced the languages of Roman Britain: Common Brittonic, a Celtic language; and Latin, brought to Britain by the Roman conquest. Old English had four main dialects, associated with particular Anglo-Saxon kingdoms: Kentish, Mercian, Northumbrian, and West Saxon. It was West Saxon that formed the basis for the literary standard of the later Old English period, although the dominant forms of Middle and Modern English would develop mainly from Mercian, and Scots from Northumbrian. The speech of eastern and northern parts of England was subject to strong Old Norse influence due to Scandinavian rule and settlement beginning in the 9th century.

The Brittonic languages (also Brythonic or British Celtic; Welsh: ieithoedd Brythonaidd/Prydeinig; Cornish: yethow brythonek/predennek; and Breton: yezhoù predenek) form one of the two branches of the Insular Celtic languages; the other is Goidelic. It comprises the extant languages Breton, Cornish, and Welsh. The name Brythonic was derived by Welsh Celticist John Rhys from the Welsh word Brython, denoting a Celtic Briton as distinguished from Anglo-Saxons or Gaels.

The Brittonic languages derive from the Common Brittonic language, spoken throughout Great Britain during the Iron Age and Roman period. In the 5th and 6th centuries emigrating Britons also took Brittonic speech to the continent, most significantly in Brittany and Britonia. During the next few centuries, in much of Britain the language was replaced by Old English and Scottish Gaelic, with the remaining Common Brittonic language splitting into regional dialects, eventually evolving into Welsh, Cornish, Breton, Cumbric, and probably Pictish. Welsh and Breton continue to be spoken as native languages, while a revival in Cornish has led to an increase in speakers of that language. Cumbric and Pictish are extinct, having been replaced by Goidelic and Anglic speech. There is also a community of Brittonic language speakers in Y Wladfa (the Welsh settlement in Patagonia).