Now, remember, this sceptred isle is supposed to have been conquered by Rome in AD 43 or so and Britain was the outer north-western edge of the Roman Empire. But, did the Romans leave in AD 383-410 to consolidate their own failing footing in Europe or had the Britons' empire been growing throughout this so-called invasion and DID THE BRITONS KICK THEM OUT.
And who were these so-called Britons with a Coelbren Alphabet? And did Boudicca speak Welsh, or (the common language of) Ancient Welsh known as Khumric? And does Khumric link right back to the Cimmeroi or Syria/Turkey via the coastal route round the Pillars of Hercules or Malta aka Gateway to the Med? And how did all this Khumric-ness survive the (supposed) Roman invasion (and clerical transformation) of Britain?
Below, you'll see how the AD 500-800 story panned out; a massive Welsh territory being gradually eroded from the east by the incursions of the Anglo-Saxons then the Danes then the Normans, isolating the (northern) Cumbrians from the (western) Cymru and the southern (Cornish).