To test the Gods' omnipotences.
He slayed his son Pelops and fed him to the gods as a test of their omniscience.
Tantalus
tantalus in the Percy Jackson series
The One Who Made a Stew of his son, was Tantalus, who tried to please the gods with his greatest gift. Pelops, his son.
Tantalus did it to his son.
Well, just one of his sons.
Tantalus being punished by the gods for stealing ambrosia and nectar, and for cutting open, boiling, and serving his son as food for the gods. They revived his son and he was sent to Tartarus to stay in a pool of water under a fruit tree. Whenever he would reach up for fruit or bend down for water they would mover away from him. His name is the origin of the word tantalize.
Tantalize comes from Tantalus who was a king that was loved by the gods and invited to parties with them, but then he offended them because he feed his own son to the gods as dinner for a party. When Zeus found out about this he punished him by sending Tantalus to the underworld were he always will have food just out of his reach and drink that moves away when he tries to drink. Others say that Tantalus was telling secrets about the gods to mortals instead of feeding the gods his own son.
Favored by the gods, Tantalus was allowed to dine with them. Taking advantage of this postition, he either made a meal for the gods of his son Pelops or he told other mortals the secrets of the gods which he had learned at their table. When Tantalus served Pelops to the gods, all except Demeter recognized the food for what it was and refused to eat, but Demeter, grieving for her lost daughter, was distracted and ate the shoulder.
He had his only son, Pelops, killed, and cooked in a great cauldron, and served to the gods.
Tantalus was the son of Zeus the god and Plouto the nymphe.
Tantalus had the brilliant idea one day to chop up his son Pelops and feed him to the gods as an offering. Demeter ended up eating one of Pelops' shoulders, but the gods resurrected him and Hephaestus made him an ivory one. Tantalus later stole food from Mount Olympus. As punishment for his atrocities, Tantalus is forever tantalized in the Underworld by water that recedes when he tries to drink and fruit that is always just out of his reach.