Roman's chosen title was the King of River Valley.
This title was of a Duke Level—essentially equivalent to the Grand Duke of Black Iron, second only to the Black Iron King.
Roman wasn't foolish enough to make enemies of the whole world.
If you rebel against Grand Duke Riptide, at worst Riptide's feudal vassals will send troops to attack you.
But dare to rebel against the Black Iron King, and all the Black Iron Nobles had reason to come after you; Black Iron traders wouldn't dare do business with you, fearing guilt by association.
Rebellion had to be done step by step.
And Roman's standard was a thorny iron ring filled with spikes on its outer circle, like a divine ring, with a Light Spear slanting inside of it.
It was recognizable enough, and it could also be changed later on.
In the end, Roman renamed Sige Town to Origin City.
From then on, Origin City would be the capital of River Valley.