So exactly who is the high muckety-muck that is so central to the story? Or rather, what is his position in society?
I don't think he's the king. All right, I have to keep an eye on that. Ripping off a story with a Lord Commander does mean that I have to beware the magnetic attraction of the old stuff. But even poking at it, he doesn't turn into a king. . . .
I think it's the politics. It is clear that his power is strictly limited by the rival lords. Which would not, of course, preclude his being king. Even quite late in the Middle Ages, nobles could overpower the king.
Still, giving him another title might help establish how he does not surpass them. A habit of venerable age. "King" at its root means "child of a family" -- that it is the royal family is not explicit -- and "duke" means "military leader." "Lord Commander" might, in fact, work. Call it a tribute to the source. . . but I'm not wed to the notion yet.