King Ryons and Family
So here is how I have set out King Ryons of the Isles. He has a brother Nero who is the father of Solinas. He has a cousin called Celinas. Ryons does the whole boasting of Hercules descent, his father being a Giant who married the sister of Celinas’ father. Celinas might be a King with him or a Saxon.
When he first tries to take Cameliard he ‘generously’ offers King Leodegrance a choice of husbands for Guinevere, Nero or Solinas, not wishing to marry her himself so he won’t be held down trying to rule Cameliard.
Not sure how close he is to Gaelic Confederates. Could be he was occupied trying to conquer Northern Ireland, with Anguish being the main power in Southern Ireland, having a sort of understanding with Ryons.
Ryons then proceeds to conquer North Wales and the Isles in between. The Gaelic Confederation might be uneasy of allying with him as they don’t want to submit to a greater authority, their plan is to smash up the whole unity. They don’t quite get that throwing off Arthur will leave Britain open to attack from Ryons and Saxons.
The detail he is King of Denmark... well could just be he has Danish descent through his mother.
Ryon is beaten first time, but could be encouraged to attack again by a messenger from Rome, who funds a mercenary force to divert Arthur enabling Ryons to renew his Welsh wars. After this Ryons is killed. I feel this works better then having him be fought after Lucius, it works more having the build-up to Lucius.
Briefly Lot does decide to join Nero due to Arthur’s success, the hope being Ryons’ forces will be weakened by the war, but they are both beaten.
Also while the Roman war is happening I imagine the remnants of Ryons’ Empire are conquered by Galehaut (Good Ryons).
As for the confusion over various Kings of North Wales and South Wales, might be various people claim the title even if they don’t really hold full dominion over that area.
Meanwhile Solinas might be a bit of a recurring villain, plotting to regain the Kingdom of Norgales and considering Guinevere promised to be him.
Of course there is barely anything about Solinas elsewhere but... what could he do? What is his fate? He could try allying with Galehaut but would Galehaut welcome the political legitimacy he could bring or wish to disassociate himself with Ryons’ family? I imagine Galehaut began his gathering of lands by putting himself as an alternative to Ryons’ rule, a type of protection.