 Lycus and his brother Nycteus were the sons of either Chthonius, one of the Spartoi, or of the nymph Clonia and Hyrieus, the son of Poseidon and the Atlantid Alkyone, or of Poseidon and the Pleiad Celaeno.He was married to Dirce and uncle to Antiope, daughter of Nycteus.Lycus and Nycteus fled from Euboea after they murdered King Phlegyas, settling in Hyria and then moving to Thebes, because they were friends with Pentheus, its king.