Britons of Strathclyde
The Britons reasserted themselves when the Romans left. The British Celtic kingdom of Strathclyde was established, stretching from the Clyde to the Solway to North Cumbria.
Then during this Dark Age period the area was subjected to much settlement and influence from overseas.
Scots
Another Celtic tribe from Ireland arrived in North Britain: the Scots. They first settled in small numbers on the Solway coast in the fourth and fifth centuries. To this and to the arrival of Fergus Mor from Ireland circa 500 we owe the fact that Tynron is now in Scotland and its inhabitants are called Scots. Fergus Mor set up the embryonic Scottish kingdom of Dalriada centred on Argyll, though this part of the world was never included in it.
Angles
Our native British people came under further pressure in the late sixth century, when Angles arrived from Northumbria, settling the coast, as at Whithorn, and exploring up the glens.
Galloway had been part of the land of Rheged, within Strathclyde, in the early sixth century, a Christian British kingdom extending from Ayrshire to North Cumbria, very powerful by 600. However, Angles had taken over by the 630s and Rheged disappeared. Tynron was absorbed into Northumbria. The new language, Old English, was introduced by the Angles from 632.
Vikings
The Vikings, between 793 and 872, were said to be the scourge of the Solway coast. Judging from the distribution of place names, Tynron Glen itself must have seen some Norse settlement. “Hass”, “grain” and “holm” are local names of Norse origin.
Britons, Angles and Scots
In 843 Kenneth MacAlpin, the first king of Scotland (called Scotia in Latin or Alba in Gaelic), united the Picts and the Scots north of the Forth and Clyde and included south-west Scotland in his first kingdom. This was when the glen first became part of Scotland, but it was only temporary.
Tynron Glen changed hands at least nominally many times between 800 and 945 AD and was never a solid part of Scotland.
The Angles, for example, held some or all of this area as part of Northumbria from 638 right up to 945. The mid seventh century bracteate from Tynron Doon is the only evidence of Angles and shows the Angles may have settled the Doon.
South-West Scotland was still part of the British kingdom of Strathclyde (or Cumbria), which was allied by blood to the Scots at various times. Cumbria was leased by the Angles to Malcolm 1 of Alba in 945. Now Tynron was definitely under Scottish control, but Gaelic was not yet spoken. Folk still spoke the British native language (Welsh), but it began to be overwhelmed by both Gaelic in the tenth century, under Scottish and Irish influences and by Old English (or Scots) under Anglian influence. The inhabitants of the glen continued to be bilingual (Gaelic and Scots English) through the Middle Ages. Even so, Welsh was still spoken in Annandale in 1100.
So the native Britons, with their Roman admixture, absorbed and still survived centuries of Scots, Angles, Vikings and even Irish-speaking Gaels, after which Galloway is named. Galloway stretched east to the Nith and so Tynron was part of it.
Tynron in Scotland
A turning point arrived in 1016, when the British kingdom of Strathclyde finally collapsed after the death of the last king, Owen the Bald, and came under lasting Scottish rule with Malcolm II and his heirs.
An increase in the population of this area between 800 and 1100 had led to the first large-scale deforestation of Shinnel Glen. More woodland was cut for fuel and timber and destroyed for cultivation and pasture. Cattle and pigs foraged freely in the woodland next to cleared areas and removed the undergrowth. By 1300 there was very little natural vegetation left in Tynron.