Historical Titles:
* Lord Chamberlain: Responsible for managing the royal household, ceremonies, and entertainment.
* Lord High Steward: Responsible for managing the king's finances and estates.
* Lord High Treasurer: Responsible for overseeing the royal treasury.
* Grand Vizier: In some Islamic kingdoms, this position held immense power and acted as the king's chief advisor and administrator.
* Chancellor: Often responsible for legal and administrative matters.
* Master of the Horse: Responsible for the king's stables and horses.
* Groom of the Stool: A more intimate position, often responsible for personal tasks like dressing and grooming.
* Secretary: Responsible for correspondence and administration.
Modern Titles:
* Royal Aide-de-Camp: A military officer assigned to assist the monarch.
* Private Secretary: A trusted individual responsible for personal and official correspondence, scheduling, and other duties.
* Royal Advisor: A trusted individual providing advice on political, economic, or other matters.
Other Titles:
* Court Chamberlain
* Master of Ceremonies
* Lord Lieutenant
It's important to remember that the role of a king's assistant can be highly complex and varied. The exact title and duties would depend on the specific context.