Sisyphus

Sisyphus (Σίσυφος) was the king of Ephyra (Corinth). Sisyphus was the son of Aeolus and Enarete. He was the brother of Cretheus, Athamas, Perieres and Salmoneus. He married a Pleiad named Merope and became the father of Glaucus (Glaucos), Ornytion, Thersander and Almus.

Sisyphus was responsible for establishing the Isthmian Games, held in honour of Melicertes, son of Athamas and Ino.

Sisyphus was famous for his cunning, and had the reputation of being the shrewdest mortal who ever lived. Sisyphus managed to recover the cattle stolen by the thief Autolycus, and in revenge, he ravished the thief's daughter, Anticleia.

Most writers said that Odysseus was Sisyphus' son, not Anticleia's husband, Laërtes (Laertes), which was why Odysseus was so cunning due to his relationship with Sisyphus and his grandfather, Autolycus.

However, I find Sisyphus being Odysseus' father rather doubtful, and inconsistent with the timeframe. Since Odysseus fought in the Trojan War, Sisyphus had a direct descendant: the Lycian leader Sarpedon, who fought on the opposite side. Sarpedon was Sisyphus' great, great grandson. Sisyphus' grandson was also the hero Bellerophon, who was a contemporary of Perseus. So Sisyphus couldn't be Odysseus' father.

When Zeus abducted Aegina, daughter of the river-god Asopus, and took her to the island called Oenoe or Oenopia, it was then named after Aegina. Sisyphus, who witnessed Aegina's abduction, told Asopus the whereabouts of his daughter. When the river-god tried to go after his daughter, Zeus had to drive Asopus away with his thunderbolts. See Aegina about her abduction.

Enraged by Sisyphus' interference, Zeus sent Thanatos, the god of death, after the shrewd king. But for a while Sisyphus cheated death. Sisyphus bound Thanatos in chains, so for a time no one died. Zeus had to later send Ares to free Thanatos. But even when Thanatos took Sisyphus to the Underworld, Hades sent him back to the surface, since his wife Merope did not allow the proper funeral rites to be performed. Merope did so from Sisyphus' shrewd instructions. So Sisyphus lived to an old age before he died once more.

Zeus punished Sisyphus in Tartarus, where he had to eternally push a large boulder uphill, only for the rock to roll back down when he neared the top. Sisyphus would then have to push the boulder uphill again. In the Odyssey, Homer didn't reveal why Sisyphus was being punished.

According to the Fabulae however, Hyginus gave us a different reason for his punishment. There was a hostility between Sisyphus and his brother Salmoneus. Sisyphus went to the oracle of Apollo in Delphi, seeking to know a way to kill his brother. The oracle answered that the children of Tyro, Salmoneus' daughter, would be the instrument of Salmoneus' death.

So Sisyphus seduced or raped Tyro. Tyro became pregnant with twins. Tyro, learning of the oracle's prophecy, killed her own sons to prevent this from happening. Their deaths caused Sisyphus to act with impiety, which resulted in Sisyphus being punished in Tartarus. What his act of impiety was, is not clear.

Maybe, the clue is in Diodorus Siculus' work, Library of History, where Sisyphus used his skill in divination, through inspection of his sacrificial victims, and discovered everything that would happen and revealed this to mankind.