In the Kingdom of Valyria, every titleholder from King down through knight is expected to maintain a feudal court to manage their territory and its community. These courts vary in complexity depending on the size of the territory and population in question; the royal court of the King is necessarily a lot more diverse, and comprised of many more departments than the court of a baron or even a town mayor.
However, they all have certain things in common. All of them need some type of administrative functionary, a role that ought to be fulfilled by clerks. Even the lowest level of feudal court, the manorial courts of hamlets and gentry, outline regulations for their tenants in a custumal. It would also behoove a gentry level mayor or knight to have a personal herald, especially if that knight is competitive in tournaments or is known for battle. Ducal and comital courts are expected to very closely mirror the royal court, complete with departments employing yeomenn who manage the various affairs of their territories at their respective tiers.