Major Northumbrian dialects are Geordie, Mackem, Pitmatic, Tyke and Scouse. Due to the roots of Northumbrian dialects, it is often said that visitors from Scandinavian countries often find it much easier to understand the English of Northumbria than the rest of the country. Apart from standard English, Northumbria has a series of closely related but distinctive dialects, descended from the early Germanic languages of the Angles and Vikings, and of the Celtic Romano-British tribes. In the ninth century, Scots in the southwest they were speaking Cumbric (a Brythonic language closely related to Welsh), in the southeast they were speaking Old English, in the northeast they were speaking Pictish, in the far north they were speaking Norse, and in the west they were speaking Gaelic.

Shetlandic has been described as 'English taught by Lowlanders to Norwegians. Shetlandic is not sufficiently typical as a dialect of English to be useful in extrapolating earlier English pronunciations. modern Shetlandic is a language closely related to English, which was adopted from Mainland Scotland by Shetlanders who had hitherto spoken a form of Old Norse. Norn words were first collected and a dictionary compiled as once the way of life changed and the objects themselves fell out of fashion, it was inevitable that their names were lost.

Gaelic replaced Norn entirely in the Western Isles. Norn died when is unknown to stipulation, both in Orkney and Shetland, was because the Northern Isles became more and more orientated towards Scotland. The Norn here shows interesting parallels with Faroese. Both the accent and a large part of the vocabulary make it a unique tongue. Shetland accent and a gradual decline of the characteristic Shetland vocabulary certainly continues throughout Shetland as they speak a language which could be written as standard English without any misrepresentation of grammar, phonology or vocabulary. Shetlandic in Lerwick is that children of Shetlandic-speaking parents, both of whom always speak Shetlandic to their children, may nevertheless speak English. Norn may have lived in Orkney and Shetland when the Northern Isles became more oriented towards Scotland by the seventeenth century. Reading into its rise or decline would be as though to read an Ogham script and not the letters.

The Pentland Skerries lie further south, close to the Scottish mainland. The name Pentland Firth can be read as meaning Pictland Fjord. The Romans were aware of the Orkney Islands, which they called "Orcades". There that they traded, either directly or indirectly, with the inhabitants. However, they made no attempt to occupy the islands. Across the Pentland Firth ferries link Caithness with Orkney but has a land boundary with Sutherland. In the wake of the Scots incursionists, followed the Celtic missionaries about 565. They were companions of Saint Columba and their efforts to convert the folk to Christianity seem to have impressed the popular imagination, for several islands bear the epithet "Papa" in commemoration of the preachers. The largest island in Orkney is known as The Mainland. Other islands can be classified as north or south of The Mainland. The islands north of The Mainland are known collectively as The North Isles, those to the south as The South Isles. During the later part of Shetland’s Pictish history, other Celtic peoples came to Shetland; Irish monks, who brought the Christian gospels to the islands. They spoke a different branch of Celtic, namely Gaelic, a language would have beeen readily understood by native Shetlanders.

In Ireland and in Wales, the language of the inscriptions this period is termed Primitive Irish. The transition to Old Irish, the language of the earliest sources in the Latin alphabet, takes place in about the 6th century. Ogham (Old Irish Ogam) was an alphabet used primarily to represent Gaelic languages. Another possiblility would be 4th century Irish colonies in Wales who came into contact with the Latin alphabet. Ogham is sometimes referred to as the "Celtic Tree Alphabet." Monumental Ogham inscriptions are found in Ireland, Wales, and the Isle of Man, with a few additional specimens found in England, Scotland and Shetland. Use of "classical" Ogham in stone seems to have flowered in the 5th–6th centuries around the Irish Sea.

Since Ogham inscriptions consist almost exclusively of personal names, linguistic information that may be glimpsed from the Primitive Irish period is mostly restricted to phonological developments. Roughly 380 inscriptions are known in total is very close to the number of known inscriptions in the contemporary Elder Futhark. The highest concentration by far is found in the southwestern Irish province of Munster. One third of the total are found in Co Kerry alone. Ogham text is read beginning from the bottom left-hand side of a stone, continuing upward, across the top and down the right-hand side in the case of long inscriptions. Old Irish Beithe means "birch-tree, " Luis, Old Irish Luis is either related to luise "blaze" or lus "herb". The arboreal tradition has caertheand 'rowan, ' Fearn, Old Irish Fern means "alder-tree", Primitive Irish *werna, so that the original value of the letter was [w]. Sail, Old Irish Sail means "willow-tree", cognate to Latin salix. Nion, Old Irish Nin means either "fork" or "loft". The arboreal tradition has uinnius "ash-tree". Uath, Old Irish Úath means úath "horror, fear", the arboreal tradition has "white-thorn".

Southern Ireland accepted Roman order of Christianity in 636 after Augustine met with the Welsh bishops. By 1312, the Scots calendar had been adopted and, as the clergy formed the bulk of the literate population of the island, the Scots language began to become more commonly used in clerical circles. Early Northumbrian is regarded as the forerunner of the Scots Language, which was called Ynglis as late as the early 16th century. (Until the end of the 15th century the name Scots (or Scottis) referred to Scottish Gaelic). There are many similarities between modern Scots (Ynglis) dialects and those of Northumbria.

Brittania was settled as early as 3000 BC, and offerings of that period imported from Cumbria and Wales left on the sacred hilltop at Cairnpapple Hill, West Lothian, show that by then there was a link with these areas. By around 1500 BC Traprain Law, East Lothian was already a place of burial, with evidence of occupation and signs of ramparts after 1000 BC. Excavation at Edinburgh Castle found late Bronze Age material from about 850 BC. Brythonic Celtic culture and language spread into the area at some time after the 8th century BC, possibly through cultural contact rather than mass invasion, and systems of kingdoms developed. Since the 3rd century Britannia had been divided into four provinces. In a late reorganisation a province called Valentia was created, which may have been a new province, perhaps including the Votadini territory, but is more likely to have been one of the four existing provinces renamed. By about 470 a new kingdom of Gododdin had emerged covering most of the original Votadini territory, while the southern part between the Tweed and the Tyne formed its own separate kingdom called Brynaich.

Cunedda, legendary founder of the Kingdom of Gwynedd in north Wales, is supposed to have been a Gododdin warlord who migrated south-west about this time. After the Roman withdrawal in the early 5th century, the lands of the Votadini became part of the Kingdom of the North, which broke up in the later part of the 5th century.

The Votadini (the Wotadini, or Votadini) were a people of the Iron Age in Great Britain and had linguistic changes as their descendants in the Sub-Roman, early medieval period were known as the Gododdin, at about the time Northumbria adopted a religious union which converted Bernicia / Anglia., and their territory was briefly part of the Roman province Britannia. Their territory was in south-east Scotland and north-east England, extending south of the Firth of Forth and extended from the Stirling area down to the River Tyne, including at its peak what are now the Falkirk, Lothian and Borders regions of eastern Scotland, and Northumberland in north east England. Their capital was probably the Traprain Law hill fort in East Lothian, until that was abandoned in the early 400s, moving to Din Eidyn (Edinburgh). Due to linguistic changes their descendants in the Sub-Roman/early medieval period were known as the Gododdin, attributed to Aneirin, the early explicit allusion to King Arthur. Their kingdom extended from the Stirling area to the Northumberland kingdom of 'Brynaich', and including what are now the Lothian and Borders regions of eastern Scotland. It was bounded on the west by the Kingdom of Strathclyde, and to the north by Pictavia.

The Damnonii were a Brythonic tribe near Kent in the area around modern Glasgow and Strathclyde in west central Scotland. Bernicia became part of Northumbria, and by 954 was overrun by the Danish kingdom of York.