I was thinking a bit about what kind of people would a king (or sovereign with any other title) surround himself with, to rule the land and to achieve his own goals. That would most likely depend on personal priorities, someone bound on expanding the borders would probably have many strategists among those to listen the most.
Even in calmer times, one would probably have representatives of the army and the diplomats to take care of any trouble, or to prevent it if possible. Those interested in expansion by force would probably hire engineers to create weapons of destruction, while those that would want to build new cities would consult architects.
To deal with the everyday life of the land, I’d say that they’d need someone to relay the problems of common people because it’s always better to solve them before they get out of hand; and representatives of the nobles, who could be tempted to conspire together for a change in leadership, if they felt they are not treated as they deserve.
Of course, the ruler’s personal goals and interests would have a significant role, for which I’d borrow example from history: Rudolf II (wikipedia) of Austrian monarchy (born 1552, crowned 1572/1576, dethroned 1608, died 1612). He was a collector of arts and curiosities and supporter of alchemy and astronomy, and so he brought several experts in those fields to his closest circles.