Cleopatra Thea (Greek: Κλεοπάτρα Θεά, which means "Cleopatra the Goddess") (ca. 164–121 BC) surnamed Eueteria (i.e., "Benefactress") was the ruler of the Hellenistic Seleucid Empire. She ruled Syria from 125 BC after the death of Demetrius II Nicator. She eventually ruled in co-regency with her son Antiochus VIII Grypus, who poisoned her in 121 or 120 BC.