Assuming King Brutus is fictional, I wondered how far the line of succession went back before it became fictional. Cassivellaunus was king when Julius Ceasar invaded in 55 BC. Gwynne's book does not list every king going back to Brutus, just some who were king when something especially interesting happened. There is a gap in the Historia between 113 BC and 358 BC. Maybe that is when the succession became fictional. There do not seem to be any other gaps. How would they keep records back then? Is there any corroboration from other sources?
The last bit on the British kings blew my mind. Around 555 the Saxons called upon King Gormund, who had conquered Ireland with a huge fleet carrying African warriors. He invaded Britain with 160,000 Africans and routed King Keredic's forces and ravaged the entire country. Gormund then handed over most the country to the Saxons. The British retreated to Wales, Cornwall and Armorica (now Brittanny). The British did rally again in the 600s. King Cadwallo supposedly reconquered it with 10,000 soldiers from Armorica, but his son, king Cadwallader was the last of the British kings. There was civil war, famine and pestilence, and the country was so depopulated, the Saxons invited their Germanic kinsfolk to come across.
I'm 53 and I have never heard of Britain being invaded by 160,000 Africans before. Is there any corroboration for this?