Laius or Laios was a king of the city of Thebes in Greek mythology, a hero and one of the key figures in the founding of Thebes. When his father Labdacus died, he went into the protection of the regent Lycus.
Laius was still at a very young age, when the twin brothers Amphion and Zethus usurped the Theban throne and killed Lycus. Some loyal citizens protected Laius and offered him passage out of the city; he was sent to the court of Pelops in the region of Pisa in the Peloponnesus, where he was raised. There, Laius abducted and raped Pelops' son, Chrisippus, and took him back to Thebes while teaching him to drive a chariot. Meanwhile, both Amphion and Zethus had died, and Laius easily ascended to the throne of Thebes.
Laius married Jocasta, the daughter of Menoeceus and descendant of the Spartoi army. According to a prophecy he received from the Oracle of Delphi, if he ever had a son, the son would kill him and marry his mother. According to a different version of the myth, the oracle said that the city of Thebes would be saved if Laius fathered no children. Nevertheless, after drinking too much one night, Laius impregnated his wife with his son, Oedipus. As soon as the baby was born, Laius gave the order that the baby be taken away to a mountain and be left to die. The shepherd who was given the order pitied the baby and instead gave it to another shepherd; the baby was eventually given to King Polybus and Queen Merope of Corinth who were childless and gladly adopted Oedipus.
Oedipus was not told that Polybus and Merope were not his real parents. So, when he received a prophecy that he must not return home because he would kill his father and marry his mother, Oedipus decided not to return to Corinth, where he thought he was from. Instead, he went towards Thebes; on the way, he came across Laius who was heading to the Oracle of Delphi because he was told his son might return to kill him. Oedipus was told to bow to the king, but he refused, and after a heated argument, he killed Laius, fulfilling one part of the prophecy. When he reached Thebes, he met Jocasta, and married her, without knowing that she was actually his mother.
Laius' descendants all had an ill fate. This was attributed to a number of different factors; Laius' raping of Chrisippus, his host's son, thus breaking the laws of hospitality; ignoring the Delphic prophecy to die childless; or because of a curse that was inflicted on his ancestor, Cadmus, by either Ares or Hephaestus.