Mnemosyne — Classical Greek Myth Library

After Cadmus and the early Cadmids, Theban kingship passes to Polydorus and then to Labdacus. When Labdacus dies (war with Athens, or divine anger, in variant notices), his son Laius is still a child. Nycteus—brother-in-law or ranking Cadmeid noble, father of Antiope—acts as regent, or shares power with his brother Lycus. The brothers are sometimes called sons of Chthonius (one of the Spartoi) or of the river-line; Apollodorus places them as holders of Theban force in Labdacus’s wake. Nycteus’s private disaster—Antiope’s pregnancy by Zeus and flight to Epopeus of Sicyon—becomes public war. Mortally wounded or dying of shame after conflict with Sicyon, Nycteus bequeaths to Lycus both the duty of vengeance and the care of Thebes. Lycus subdues Sicyon, recovers Antiope, and rules Thebes as tyrant-regent, holding the throne that should revert to Laius. Under Lycus and Dirce the city is an occupied house: the rightful Labdacid heir is sidelined or exiled (Laius will grow at Pelops’s court), while Zeus’s hidden twins grow on Cithaeron. Thus Nycteus and Lycus are not a separate dynasty so much as a **usurpation setup**: their regency explains how Amphion and Zethus can storm a Thebes that is neither Cadmus’s nor yet Laius’s, kill or oust Lycus, and build the walls—after which the Labdacid line (Laius, then Oedipus) returns. Without this hinge, the Amphionid interlude and the later Oedipus saga lack a political bridge.