The Queen's Gambit — Deborah Chester

The throne was her destiny--until Princess Pheresa lost her groom, Mandria's heir, to the dark magic that consumed him. Now Pheresa's fate is uncertain, even when the great King Verence names her Princess Royal--because the title comes with one condition: She must take Lervan, a man of acceptable birth and rank, as her husband. Reluctantly, she agrees.

Then, without warning, the old king dies. And Pheresa succeeds to the throne.

But all is not well. Many fear that Pheresa has been weakened by the evil magic. Her enemies are strong. Her husband plots against her. And her only ally is the last man she would ever choose--and the one man she should never love.