The parish at Kingarth at the South of Bute has been considered the only one early enough to be associated with the gift of the parishes to the recent Cluniac foundation at Paisley Abbey by Alan Fitzwalter in 1204, specifying the site as the lands assigned to it by Saint Blane himself who earlier than most of the surviving monuments on Iona is a comparable but more modest foundation on the Isle of Bute, associated with Saint Blane in the late 6th century. Whithorn had a major role in the introduction of Christianity into Scotland probably long before Saint Columba. By the time of this late rebuilding its allegiance however was to the English metropolitan of York much later than elsewhere in Scotland.
In 1163, Walter FitzAlan issued a charter for a priory to be set up on Paisley Abbey, a Cluniac monastery. It was raised to the status of abbey in 1245. In 1307, Edward I of England had the abbey burned down. It was rebuilt later in the 14th century. Paisley Abbey is the burial place of all six High Stewards of Scotland.
In Gallovidian Gaelic (an extinct Goidelic dialect), it was called Rosnat, or Futarna, the latter a version of the Anglo-Saxon name (Gaelic has no sound corresponding to English 'wh'). Much used in the Middle Ages by pilgrims arriving by boat. Gallovidian Gaelic was formerly spoken in Southwest Scotland. It was spoken by the independent kings of Galloway in their time, and by the people of Galloway and Carrick until the early modern period and once spoken in Annandale and Strathnith. Old Irish can be traced in the Rhinns of Galloway from at least the fifth century. Although Galloway was peripheral to Scotland until 1234, in the aftermath of the dissolution of the Lordship, Galloway and Galwegians became critical. Ferchair Mac an t'Sagairt, who was apparently the grandson or great-grandson of Gillandres, led most of the western tribes, and for his prowess, the Celtic earldom, which was then finally annexed to the Crown and made a feudal appanage, was conferred on him with the title of Earl of Ross, and he is so designated in a charter dated 1234 AD.
In the Annals of the Four Masters it is stated that "Somerled, son of Gilbrigid, king of Innsie Gall " (i.e., the Sudreys), died in 1083. It seems evident from the repetition of the personal names that this Somerled was the father of Gil-Adomnan, and that, being originally and properly Lord of Argyle, he had also acquired some of the adjacent isles, as Jura, Mull, etc., enough to procure him the title of Insular king. In many ways, the Scottish Wars of independence were just a Galwegian civil war, with the Bruces the successors of Gilla Brigte mac Fergusa and the Balliols the successors of Uchtred mac Fergusa. Under the post-1234 Franco-Gaelic lorship were several powerful kin-groups as it was probably through these groups that Galwegian society operated for the remainder of the Middle Ages. The placenames Balmaclellan and Balmaghie may represent the site of chiefs' residences. But none of these varieties are Irish Gaelic, but rather reconstructed from things such as place-names as Gallowegian Gaelic seems to have borrowed certain words from Old English and evidence of a bardic class can be found in such placenames as Dervaird (Doire a' Bhaird) and Loch Recar (Loch an Reacaire). The influence of the Anglian Bishopric of Whithorn, with the Norse Gall-Gaidhel include Kirkcormac, Kirkmikbrick, Kirkinner, Kirkcolm, Kirkmabrick. In these names, the first word is Germanic and the second Gaelic. For example, the name Gille Cuithbrecht (= Manx, Giolla Cobraght) means devotee of St. Cuthbert.
The Gall-Gaidhel (the Gaelic Norse), who gave their name to the area appear to have settled in the ninth and tenth centuries. Many of the leading settlers would have been Norse speaking, but this would not appear to have been to the same extent as in other Norse-Gaelic regions, such as parts of the Hebrides and Sutherland-Caithness. It is quite possible that even as late as the twelfth century, Cumbric (a Brythonic language related to Welsh) was still spoken in Annandale and lower Strathnith. The likely eastern limit reached by the language was the Annan. The reason for that is that Gaelic placenames disappear quite rapidly after this boundary, although a handful of Gaelic names also appear in the Isles and Cumbria. It is thought that Galwegian Gaelic probably had more in common with the Manx and Ulster Irish than with Scottish Gaelic as spoken in the Highlands. And though, the Galwegian language died out somewhere in the two-century period between 1600 and 1800, with the balance of evidence strongly indicating an effective disappearance in the seventeenth century. It is notable though, that nearby areas such as the Isle of Man, east Ulster and Arran all had native Gaelic speakers into the 20th century.