and are briefly mentioned in Vergil 's Aeneid when Aeneas is coming back from the Underworld. Hesiod establishes them in his Theogony as sons of Nyx either through parthenogenesis (Hesiod Theogony 212; Sappho Frag 63, Statius Thebaid 10.112) or with Erebus (Hyginus Preface, Cicero De Natura Deorum 3.17). According to Euripides