In 325BC, a Greek geographer first described the islands to the north of the main European continent as ‘pretanic’ (referring to the style of speech found there). This was later bastardised by the Romans into ‘Brittonic’ and then further bastardised into ‘Brythonic. The collected islands we know today as ‘Britain’ became known to them as ‘Britannia’ (Brython) and the native peoples living there as the Brythoniad.
When Rome abruptly abandoned the most northern point of its empire in the 4th century AD, rampant warring saw the island we know as Britain devolve from ‘Roman’ back into a heap of traditional tribal regions linked by related Celtic belief systems and languages. The dominant one was the Cymry which we’ll look at in the (next post).