Queen Cersei I Lannister was the twentieth ruler of the Seven Kingdoms and the widow of King Robert Baratheon, with whom she had her sole trueborn child. Cersei assumed the throne under the name of Cersei of the House Lannister, the First of Her Name, Queen of the Andals and the First Men, Protector of the Seven Kingdoms, making her the first officially recognized Queen Regnant in the history of Westeros.