In the Middle Ages, some kingdoms were obviously more prestigious than others. This was shown by such things as Edward III putting the fleur-de-lis first in his coat of arms over the three lions, because the title "King of France" was considered higher than "King of England". But what would the overall list be? I'm guessing Holy Roman Emperor would have been considered better than the King of France? But what about Poland, Hungary, Castile, etc?