User blog comment:Zippertrain85/Harkon's backstory?/@comment-6573099-20130508034601/@comment-3217145-20130508034849

He doesn't have to. There is no exhaustive list of kings anywhere, and any Forsworn could claim they're the "king" of whatever they want. The legitimacy of that claim is only based on the support the claimant has behind them. If he said "I'm king now" and defeated anyone who came to say "no you're not," then guess what, he's a king.