[QUOTE
- Magnus Maximus is more successful, and or Theodosius sets up a Triumvirate, with him in charge of Britain and Gaul. He/His successors subsequently retreat to Britain after the rise of the Vandals, and or Franks.
- Constantine III, moves into Gaul and upon becoming Co-Emperor, keeps his troops on the border, or remains in Britain, or is forced back into Britain.
According to some Uthur Pendragon was a son of either Magnus Maximius or Constaintine III.
Uthur Pendragon's son Arthur came to wear purple until he had several misfortunes - one of them was defeating Huiel (Gildas' brother) battle, Arthur pardoned said brother, Mordred is found is found playing hide-sausage with Hueil and Gildas's sister (Cywyllog), Hueil turned bandit, Arthur defeated Hueil and executed him, afterwards Gildas burned all his books concerning the reigns of Uthur and Arthur, some time later Mordred turns on Arthur and bad things happen, and Gildas took exile in Brittany writing bad excommunications of Arthur's successors.[/QUOTE]
This is interesting! Arthur is said to have been alive around the late 5th and early 6th century, which could maybe, by a stretch, work if Constantine III lived a bit longer to have Uther, who lived for a long period of time (50 years or so) before Arthur.
What if Constantine had retreated to Britain after invading Gaul, and kept the self-declared title of Emperor alongside his army at his army's maximum extent?
I've tried researching this, but would troops from Gaul refuse to live on Britannia, away from their home? I understand that often families of soldiers would be close by, but I don't think this was the case with Constantine due to it being more of an organised rebellion than a legitimate army, so I'm wondering if Constantine would have been able to move these soldiers from Gaul to Britain permanently without facing another rebellion. British-Roman soldiers obviously did care about Gaul to an extent, because it's invasion by Franks/Vandals was what caused them to elect Constantine in the first place. Furthermore, Constantine III wasn't the soldiers first choice either, but in fact came after the soldiers straight up murdered the last leader because they didn't think he was competent, so if he began to retreat, he's going to need to convince the soldiers that he is not losing the war.
I'll try to iron out these sort of things, but I think the Constantine III idea is what I'm going to go for as a POD, due to it being later, meaning there will be fewer butterflies regarding the fall of the WRE and the survival of the post-Roman kingdoms and the ERE. Thanks for the suggestions!