Heraut has many titles: the Centurion King, King of the Brigantes, heir of King Coel the Old, and especially King of One Hundred Knights.
King Heraut rules over a Cymric country but is himself of Roman lineage and clings to the Roman way of life. (Hence his styling as The Centurion King.) Ruling over the former capital of a Roman province and the second-largest city in all of Britain, Eburacum, he takes great pride in his title.