The name of the city founded by Kentigern has been differently spelt at different times. In the manuscript of the Life by Jocelin in the British Museum – the one which Pinkerton followed – the original name is said to have been “deschu.” The first church, the manuscript bears, was established “in villa dicta deschu quæ nunc vocatur glaschu.” What this word deschu could mean has given rise to much conjecture, and has puzzled many archæologists. None of the writers have attempted to explain it, and, indeed, it is meaningless. I mentioned it to Mr. Whitley Stokes, one of our best Celtic authorities, and with the instinct of a true archæologist, he made it clear at once. He suggested that what had taken the form of the letter d in the word was nothing more than the letters c and l placed too close together in the original manuscript; that the monk, copying only by the eye, had mistaken them for the letter d (which is just c and l joined), and that the word is cleschu, pure Welsh, the same as the glaschu which Jocelin says the place was called in his time. That this is the true explanation I have no doubt, and it is an instructive example of the manner in which names become unintelligible by the carelessness of copyists. Since I obtained that explanation my attention has been called to another example, mentioned by Mr. Skene, of the very same mistake made by the transcriber of the history written by Asser in the end of the ninth century. In narrating the subjugation, by the Danes, of the Picts and the Strathclyde Welsh or Britons, the names of these nations are written Pictos and Strathduttenses. The last word should be Strathcluttenses, the d, as in the case of deschu, being put for c l.
In the earliest of the charters the name is written Glasgu. but on the oldest of the city seals, of which impressions exist as early as 1325, the legend is “Sigillum comune de Glagu.” How it came to be so written I do not know. I suppose it was intended for a contraction, but if so it is an unusual one. It was certainly not a mere error of the artist who cut the seal, in omitting the s by mistake, as I have found the same spelling in documents under the hand of the accomplished prelate Wyschard, written while he was a prisoner in England, shortly before the battle of Bannockburn. One of these is a petition addressed by the bishop to Edward II., in which he prays the king “pur Dieu et pur charite et pr salvacion de sa alme,” to allow him to dwell in England within certain bounds, and in this document he styles himself “le Evesque de Glagu.” The petition appears to have received no attention, and again the unfortunate prelate, in a second appeal, prays, “a nre seignr le rey et a son conseyl voyle fere grace de sa deliveraunce a demorer deinz Engleterre denz certynz boundes al volonte le roy;” and here also Wyschard designs himself “le Evesque de Glagu.” In other documents of the time the name of the city appears in different forms. On the seal of the chapter used in 1180 it is called Glesgu. In a letter by the Earl of Warrenne and Surrey to the English king, in 1297, he makes mention of the “evesque de glasgeu.” In another letter addressed by the same nobleman to his sovereign he speaks of “Sire le evesk de Glascu*.” In a letter by Hugh de Cressingham to the King of England, written in the same year (1297), the name appears in one place as Glasgu and in another as Glasgou – very much its present form. In a charter by Robert III. in 1324 it is written Glasgw. In a charter by John Stewart, lord of Darnley, in 1149, it is written Gleschow; and in the will of Archbishop Betoun he designs himself Archevesque de Glasco.
The local historians have interpreted the name as meaning “grey smith.” This is a mistake, and it has arisen from their seeking its origin in the Gaelic of the Scottish Highlands. An archæological friend and an excellent Gaelic scholar, looking for the origin of the name in the same direction, suggests “clais,” a ravine or hollow, and “dhu,” dark. But this part of Clydesdale was a Welsh settlement, and the origin of the name is to be sought in the British branch of the Celtic language. It means, I think, the beloved green place – “glas,” viridis, and “cu” or “gu,” carus, as in Munchu; and it probably took its origin from the spot where Kentigern and Columba met, and where the first church was erected.