Roman Emperors and the \"King\" title

[Epictetus]

Anyone following this thread might be interested in Karin Mosig-Walburg's theory that Hannibal(l)ianus held a "special position" overseeing the client kingdoms of Sophene, Iberia and the Lazi. Pontus fell within the remit of Constantius (II), who governed Asia.

I suddenly remembered something I read in Mitchell's Anatolia. It struck me as noteworthy at the time but I never pursued it. During the Republic, someone (Pompey? He would make sense.) appointed a Roman citizen as king over one of the smaller Anatolian client states. I don't think it was Pontus. I wonder if he had to surrender Roman citizenship.

If I could read German I imagine I would be interested in what Mosig-Walburg says. :-(