The Terrible Queen (Catherine de Medicis)

Catherine de Medici, whom the novel describes as the terrible queen, is not a fictional character created by the writer's imagination, but rather a real historical character. Catherine de Medici was the queen of France, but without a throne. She worked to consolidate royal power when she was guardian of each of her three sons who were kings of France. She exercised great influence over each of them, and over her daughter Margaret, who also became Queen of France. She was practically the de facto ruler of France for thirty years.
Thus, she became a dramatic character par excellence, which prompted the famous novelist Alexandre Dumas (the father), who is known for his historical novels, to write an entire novel about her, and Catherine de Medici or Caterina de Medici.