We have next to inquire as to the period within which this race of Cadmeans held sway in Bœotia, the district where alone we hear of them. When did they begin, and when did they close? The extra-Homeric tradition would throw Cadmus back to one of the very earliest periods, which would appear to be included within Homer’s knowledge upwards. The generations are arranged as follows: 1. Cadmus. 2. Polydorus. 3. Labdacus. 4. Laius. 5. Œdipus. 6. Eteocles and Polynices. The last-named brothers are contemporaries of Tydeus. It follows that Cadmus is placed seven generations before the Trojan war; he is made contemporary with Dardanus, and he appears in Greece about three and a half generations before Minos came to Crete. Now this is not the presumption, to which the Homeric text would give rise. For it does not seem likely that, if a family of an active race like the Phœnicians made their way into Greece, and managed to establish a sovereignty within it seven generations before the _Troica_, upwards of a century should elapse before any other adventurer was found to repeat so advantageous a process. Further, the Cadmeans were in Thebes. But Cadmus was not its founder. It was founded, as we are told in the Eleventh Odyssey[475], by Zethus and Amphion, sons of Jupiter and of Antiope, daughter of Asopus: two persons who have thus, on both sides of their parentage, the signs of being the first known of their own race in the country. From the appearance of Antiope in the Νεκυΐα, where none but Hellenic and naturalized Shades are admitted, we may infer that Amphion and Zethus were not Pelasgian but Hellene. Again, as they _first_ founded and fortified Thebes, they must have preceded Cadmus there. What then was their probable date? In the Νεκυΐα, so far as regards the women, Homer gives some appearance of meaning to introduce the persons and groups in chronological order. The first of them all is Tyro[476], who seems to have been of the family of Æolus, and to have lived about four generations before the _Troica_. The next is Antiope, mother of Amphion and Zethus. After her come (1) Alcmene, mother of Hercules, (2) Epicaste, mother of Œdipus, and (3) Chloris, mother of Nestor. All of whom belong to a period three generations before the war. After these follow Leda and Ariadne, with others whose epoch the text of Homer does not enable us to fix. But Ariadne, the bride of Theseus, and aunt of Idomeneus (the μεσαιπόλιος), stands at about one generation and a half before the war: and Leda, as the mother of Castor and Pollux who were dead, and of Helen whose marriageable age dated from so many years before the action of the Iliad, as well as of Clytemnestra, belongs to about the same date.