Latin was the written language in dark age Britain thanks to four centuries of Roman rule but only Monks and the very wealthy could read and write in Latin. The spiritual and political leaders of Britain shared their news, culture and business verbally in the tongue of the day – Brythonic. This made knowledge both equitable (even the poor could understand the common tongue) and accessible (and the role of Bards of fundamental importance and power in being the medium of communication).
Today, Welsh is the closest remaining language to ancient Brythonic and it still resonates with a very old, very Celtic feel quite distinguishable from Gaelic or Scots Gaelic. When the western peninsular we know as ‘Wales’ did finally succumb to the spreading Anglo-Saxons, they managed to hold onto much of their language, unlike the rest of the country. They have retained a distinct cultural identity (going through somewhat of a renaissance recently) and the country is officially bilingual, speaking both English and Welsh.
The words ‘Welsh’ and ‘Wales’ are of AngloSaxon origin from Wælisc (the people) and Wéalas (the land). The terms initially referred to anything or anyone that the Anglo-Saxons associated with the early Britons (Celts), but as the Anglo-Saxon culture subsumed the original cultures of what we now know as England (Angleland, land of the Angles) the ‘Wælisc’ and their unique culture congregated in Wéalas (Wales).
Of course, the locals didn’t call themselves that at all and they didn’t distinguish between the people and their constantly shifting lands. Both were called Cymry but in the 16th century Cymry became synonymous with the people and Cymru with the land. The language they speak is Cymraeg. This still stands today.
The Welsh weren’t the only ‘Wælisc’
Here’s an interesting little side fact. It appears the Welsh were not the only peoples that the Anglo-Saxons applied the term to. The phrase ‘Cornwall’ comes from ‘Wealas of the Horn’ (corn + weal) and the name Wallachia was applied to the natives of Roman Carpathia. This points to a much older useage and historian Edward Dawson posits that the Celts, themselves, may have used a phrase that informed the Germanic ‘Wal’.
While the Greeks called the Celts Keltoi and the Romans called them Celtae there are records of actual Celtic tribes called Galati and Galaci. In Celtic languages, G and K are interchangeable—in my book ‘Sacrifice’ you see this with Caer Gynyr being the stronghold of Cynyr Forkbeard—but Dawson goes a step further, explaining that the people we know as ‘Celts’ often put a ‘G’ in front of words that stared with ‘W’ (example: the Germanic word ‘wood’ becomes ‘gwood’ which with regional dialects within the Celts became ‘coed’ in Wales). Therefore, Dawson postulates, if the original name of the (Germanic) Celts was the ‘Walt’ then to the Celts it became Kwalt (koo-elt /kelt) but to the Angles and Saxons it remained Walt and then became Wal in time.
So Dawson speculates that the Welsh are not foreigners as such but were, literally, the Celts of Brython.