Upvote:-2
There was no Wales in Viking times or before hand. Albion related to traders at see who called the white cliffs of Dover the (white) Albion land. Nothing to do with Scotland or Wales. The wild lands of the Pict not Alba as some repeatedly say is correct. Albion relates to Dover cliffs only. First sight of Britainia until the Roman who used Britanus as base. Built a wall across England to stop the Pict mingling with them. Wales as Cymry was also at first linked in with England but blue faced warriors from the hills put up resistance but Rome moved in on them fast and cleared them out .Built CARDIFF after Chester to protect interest and involve Business men from Roman world to trade in Chester all over Britanicus. The Normans took over and Wales as subdued as trouble makers .Scotland was secured owing to location for defensive safety doing away with border so to defend all land from attach. Scotland was part of all same as England but England was warm and they lived there instead. All was once part of France joined up to Britani and so my guess it is why Romans called us Britain
Upvote:6
I believe it's thought to be a hellenisation of the common brythonic form *ėlβɨð 1 giving Albíōn and latinised as Albiōn.
That common Brythonic form giving Old Welsh elbid, meaning that native word wasn't replaced and continues to the modern day with the Welsh word elfydd "earth, world, land, country, district".
The Common-Brythonic meaning is thought to be “upper world” (as opposed to underworld) so in the British context it likely wasn't used as a term for the island of Britain per se but the world in general; the fact that it comes into Latin and Greek as a word for Britain suggests the Britons they encountered were referring to the island as the "world" and travellers took the word to just mean the island.
I've not found any stringent sources beyond Wiktionary and Wikipedia so take all this with some healthy scepticism. But, if true the Britons would of used a Brythonic form of the word akin to *ėlβɨð, and by the time any idea of 'Welsh' identity was starting to ferment elbid, and later elfydd, unless they were speaking Latin, in which case they might have used Albiōn.