Polydorus was the son of Cadmus and Harmonia, and Labdakuys (Labdacus) was the son of Polydorus (and Nycteis). He founded the House of Labdacus, which includes Laius, Oedipus, and their descendants.

Polybus and Labdacus

Pentheus, Actaeon, Labdacus, Melicertes, Learchus.

Laius was father of Oedipus by Jocasta and the son of king Labdacus of Thebes.

Theban King Labdacus is Theban King Oedipus' paternal grandfather. Labdacus' son is Theban King Laius, and his daughter-in-law is Theban Queen Jocasta. Jocasta and her brother, Theban King Creon, are the children of Menoeceus. Both Labdacus and Menoeceus are descendants of Cadmus, the founder and first king of Thebes. So those who occupy the throne of Thebes are closely related.