Over the next five hundred years with the founding of Scotland and spread of Christianity across the north of Britain by the Columban Church the Gaelic language slowly moved eastwards and southwards across the lowlands.
When Northumbrian lands were incorporated into Scotland in the 11th century Gaelic became the prestige language there and had some influence, but the south east remained largely English speaking.
Scholars of the language generally use the following chronology:[1] The nature of early forms of the language are obscure due to Viking plundering and destruction, Edward I of England's removal of the national records and their subsequent loss, the destruction of the monasteries in border warfare, and vandalism during the Reformation.
[2] According to linguist Paul Johnston, Scots descends "from a radically restructured, Norse-influence Northumbrian going back to the Danelaw proper as much as from the original dialects of the Bernician settlers.
Although the military aristocracy employed French and Gaelic, these small urban communities appear to have been using English as something more than a lingua franca by the end of the 13th century.
Some loan words entered the language resulting from contact with Scottish Gaelic, often for geographical features such as ben, glen, crag, loch and strath; however, there are several others like bog from bog (moist or damp), twig (catch on) from tuig (understand), galore (lots of) from gu leòr (plenty), boose or buss from bus (mouth), and whisky from uisge-beatha (water of life).
In 1559 William Nudrye was granted a monopoly by the court to produce school textbooks, two of which were Ane Schort Introduction: Elementary Digestit into Sevin Breve Tables for the Commodius Expeditioun of Thame That are Desirous to Read and Write the Scottis Toung and Ane Intructioun for Bairnis to be Learnit in Scottis and Latin.
In 1560 an English herald spoke to Mary of Guise and her councillors, at first they talked in the "Scottish tongue" but because he could not understand they continued in French.
[7] By this time Scots had diverged significantly from its neighbour south of the border and had become the vehicle for an extensive and diverse national literature.
Elocutionists such as Thomas Sheridan and John Walker were employed to teach Scots, both in London and Scotland, the formalities of proper English.