Well, we have a Parthian King, but he likes to spend a lot of time on the horse. Our Great King, of course, is Aslan, but He likes to delegate.
The pirates are hung up on their heirarchy. All we really need is a strategy. The Parthian King is placing his fiery archers. My limpet mines will work if they stray into the harbor and divers can get close enough. In the meantime - we're knights. The strength of pirates is their ship; the strength of knights is their fortress. Let us send cannon to our highest towers, overlooking our bay and the approach to the harbor. We can set up makeshift ovens to heat the shot, so if they dare approach, we can bombard them with heated shot - plunging heated shot.