Many times in history, one country has invaded another, taken over -- and left the previous head of government in place as a puppet.
If your character is such a puppet, how does she feel about it? Do the common people know that he's a figurehead? Is she blamed for what happened? Resented? Are there plots to take back control, and if so, do they involve your character -- actively, as a target, or as part of the new new regime?
Or maybe your character has helped to conquer another country and is putting a puppet on the throne. Does he stay there to keep tabs on what the nominal ruler is doing? Is she sympathetic to the country's people? Does he just want to wash his hands of all the politics and get back to the battlefield?
Who is pulling the strings and why? And how are others reacting?