> ... and from Anglo Mythology (well mostly stories about King Arthur).
Arthurian legends are great, but there’s a whole parallel set of legends set in the same time period. Ever read Orlando Furioso? It takes place in France and Italy during the reign of Arthur. In Orlando Furioso I found out that Morgana was the Lady of the Lake, and that Merlin had her make two Excalibers, because he knew one would be broken. When Arthur broke the sword and cast it into the still water of the lake, Morgana caught it, took it to the bottom of the lake and brought up the duplicate Excaliber.
Merlin features prominently in Orlando Furioso. You wouldn’t believe the number of holes in the Arthurian Legends that are filled in.
On the other hand he gave away the family farm to the Saxons, and they had to move from there to Brittany which had recently been seriously depopulated by whatever it was caused the Dark Ages to begin.
Now, from that point on there end up being SEVERAL sources of Arthur stories. First, the Welsh version, then the Breton/Briton version ~ and the Brocelinda, then all the way across France to the headwaters of the Rhone there's a third source.
These things were possible at the time because there was hardly anyone around to care one way or the other. Merlin had to replant the grapes in Brittainy, Beaujolais and along the Rhone Valley for that matter, and that was a whopping big job, except there weren't many customers around so he and a couple of Saxon slaves could probably get the job done in short order.
Notice that no one ever buys or sells a horse ~ they just go out to the fields and get one. All the horses were wild for a while until people bred more riders! Wolf attack stories make their way back into all the European folk tales there in the 6th and 7th centuries (real wolves too)
One, or maybe two of the stranger things to happen in that period was the dispatch of Jain missionaries to the ends of the Earth by several Jain kings in India. A couple of these fellows made it all the way to England ~ right there at the time King Ad was giving away the family farm. They moved to Brittany as well.
They left behind sermons that heavily criticize the local petty kings and nobles for fighting wars. A Jain thing!
This is a bit short of an Ancient Astronauts scenario, but the missionaries were real, they came from India, and they probably seemed quite Spock-like to the locals. One of them saw buildings fall down when they were pulled into the sky ~ by something.
No doubt the Pope had a good laugh with these fellows ~ they got to Europe just in time to see it turn nasty.
As the battle of Roncesvalles was about 280 years after Badon Hill, I going to call shennagins on "the same time period". And as Orlando Furioso was published only 30 years after Le Morte d'Arthur, I'm not too surprised that a number of improvements were made to the plotting.
What Ludovico Ariosto did was write a crossover fanfic combining the universes of Mallory's Le Morte d'Arthur and Matteo Maria Boiardo's Orlando Innamorato