It was during Lycus’ second guardianship that Amphion and Zethus invaded the country with a band of men. And those who were anxious for the continuance of Cadmus’ race withdrew Laius, and Lycus was defeated in battle by the sons of Antiope. And during their reign they joined the lower town to Cadmea, and called it Thebes from their relationship to Thebe. And I am borne out by the lines of Homer in the Odyssey:[49] “Who first gave its towers and seven gates to Thebes, for though they were strong, they could not dwell in a spacious unfortified Thebes.” As to the legend about Amphion’s singing and the walls being built as he played on his harp, Homer has made no mention of it in his poems. But Amphion was famous for music, and from his relationship to Tantalus learnt the harmony of the Lydians, and added three strings to the lyre, which had previously had only four. And the author of the poem about Europa says that Amphion was the first who played on the lyre, and that Hermes taught him how: and that by his strains he drew stones and animals. And Myro, the Byzantian poetess who wrote epic and elegiac verses, says that Amphion first erected an altar to Hermes and received from him the lyre on it. It is said also that in Hades Amphion paid the penalty for his railing against Leto and her sons. This punishment of his is mentioned in the poem called the Minyad, and there are references in it both to Amphion and the Thracian Thamyris. And when the family of Amphion was destroyed by pestilence, and the son of Zethus was slain by his mother for some fault or other, and Zethus also died of grief, then the Thebans restored Laius to the kingdom. When Laius was king and wedded to Jocasta, the oracle at Delphi told him that he would die at the hands of his son, if Jocasta bare him one. And that was why he exposed Œdipus, who was fated after all when he grew up to kill his father. He also married his mother. But I do not think he had any children by her. My authority for this view is Homer, who in his Odyssey has the following lines.[50] “I also saw the mother of Œdipus, beautiful Epicaste, who did a horrible deed, unwittingly marrying her own son, for he married her after slaying his father, but soon the gods made it publicly known.”