He killed guests and travelers in his palace, a violation of guest-obligations, which fell under Zeus' domain, thus angering the god. King Sisyphus promoted navigation and commerce but was avaricious and deceitful. Sisyphus was the founder and first king of Ephyra (supposedly the original name of Corinth). He was the grandfather of Bellerophon through Glaucus, and Minyas, founder of Orchomenus, through Almus. Sisyphus married the Pleiad Merope by whom he became the father of Glaucus, Ornytion, Thersander, Almus, Sinon and Porphyrion.

He was the brother of Athamas, Salmoneus, Cretheus, Perieres, Deioneus, Magnes, Calyce, Canace, Alcyone, Pisidice and Perimede. Sisyphus was formerly a Thessalian prince as the son of King Aeolus of Aeolia and Enarete, daughter of Deimachus. German mythographer Otto Gruppe thought that the name derived from sisys (σίσυς, 'a goat's skin'), in reference to a rain-charm in which goats' skins were used. Beekes has suggested a pre-Greek origin and a connection with the root of the word sophos (σοφός, 'wise'). Through the classical influence on modern culture, tasks that are both laborious and futile are therefore described as Sisyphean ( / s ɪ s ɪ ˈ f iː ən/). Zeus punished him for cheating death twice by forcing him to roll an immense boulder up a hill only for it to roll down every time it neared the top, repeating this action for eternity. In Greek mythology, Sisyphus or Sisyphos ( / ˈ s ɪ s ɪ f ə s/ Ancient Greek: Σίσυφος Sísyphos) was the founder and king of Ephyra (now known as Corinth).

Glaucus, Ornytion, Almus, Thersander, Sinon and Porphyrion (a) possible (half-)siblings by Aeolus: Aethlius, Cercaphus, ? Ceyx, Macedon, Mimas, Minyas, Arne (or Antiope, Melanippe), Iope and Tanagra (a) Salmoneus, Cretheus, Deioneus, Magnes, Perieres, Athamas, Alcyone, Calyce, Canace, Peisidice and Perimede Persephone supervising Sisyphus in the Underworld, Attic black-figure amphora, c. 530 BC, Staatliche Antikensammlungen

Sissy tasks