User blog comment:Zippertrain85/Harkon's backstory?/@comment-121.219.169.69-20130518100414/@comment-124.181.209.130-20130520075217

It's possible that there was no High King during Harkon's time, since we don't know exactly when he was around. Or maybe his kingdom of his was not in Skyrim at all? Besides there us little information about the First Era in general.

Regarding people rebelling, who knows what happened? It might have been slaves bought from Morrowind that he sacrificed. Or maybe a specific population outside of his own. Primitive tribes?

It could also be bad writing on Bethesda's half.