Cersei Lannister

Cersei became the Queen of Westeros through her marriage to King Robert Baratheon, who subjected her to abuse throughout their relationship. Her father, Tywin, orchestrated the marriage after his plan to marry her to Prince Rhaegar Targaryen, whom she adored in her youth, fell through. Robert seized the Throne with the assistance of the Lannisters, effectively ending the Targaryen rule. Cersei has been entangled in an incestuous relationship with her twin brother, Jaime, since childhood. All three of her children are fathered by Jaime.