Agrippina

Agrippina was the sister of the third emperor of Rome, the mad Caligula, whom she may have had a relationship with. Years later she went on to marry her uncle Claudius, the fourth emperor of Rome. She had him poisoned in 54 A.D. so her son Nero could become emperor. She may have had a relationship with her son as well. She was put to death by Nero during his reign.