Since Hercules was immortal, dying was a problem. He should not have been able to die, but before addressing the how of his ending his life, it is necessary to address the why. Why on earth would a hero still in the full vigor of his manhood want to shake off his mortal coil?
Caustic Garments
In the story of Jason and Medea, Jason wanted to get rid of Medea and marry a princess, Glauce of Corinth. Although Medea warned Jason that he was hurting her and their two children, she eventually pretended to go along. She sent their two children to the palace, bearing a wedding gift for the princess. This gift was a gown that contained a body heat-activated caustic substance. When the princess started to burn, her father, Creon, embraced her, and so both Creon and his daughter Glauce burned to death. Something similar happened to Hercules, with the same kind of jealousy as motive.
The Hercules story is not a complete doublet. The poisoner was, again, the current wife, but the victim was not a new wife. Instead, the victim was the straying husband; in this case, Hercules. The object of jealousy was a beautiful young woman named Iole.
A Gullible Wife and the Centaur's Revenge
Deianeira -- a name Christopher Faraone (in his Harvard University Press book Ancient Greek Love Magic) says has a popular etymology of husband-slayer -- was the name of Hercules' traitorous wife, but unlike Medea, she did not know what she was doing. She thought she was using a love potion. She had received the poison as a gift from a lecherous centaur who told her to save it for just such a purpose. The name of the centaur was Nessus. He had been commissioned by Hercules to help his second wife Deianeira across a river when she was traveling with her husband, but Nessus had other plans, the result of which was that Hercules had to rescue his wife. Hercules shot the centaur in the heart with one of his hydra-poisoned arrows. As this fast-acting poison ran its course, Nessus, who (to give Deianeira the benefit of the doubt) may have appeared to be dying from the accuracy of Hercules' aim, rather than from invisible poison, told Deianeira to take some of his blood to use as a charm should Hercules start to lose interest in her.
When Hercules put on the "love-potion" soaked garment, a gift from his wife, he had no reason to be suspicious. It is hard to say which of them would have been more surprised by what happened to Hercules. She hanged herself when she realized what she had done. His skin started to burn. The pain was unspeakable, unbearable. Water did nothing to ease the pain. Hercules could not remove the garment without ripping himself apart.
The Death Prep and Details
Historian Diodorus Siculus (fl. mid 1st century B.C.) says Hercules sent Iolaus to the Delphic Oracle to find out what he should do. The answer was to build a pyre on Mt. Oeta and look to the decision of the gods about his fate.
Hercules ordered a pyre to be built on Mt. Oeta. No problem there, but he did have trouble finding someone willing to light the pyre. When, at last, Philoctetes agreed to do so, Hercules rewarded him with the gift of his poison-tipped arrows. More than a decade later, the presence of an arrow-bearing Philoctetes, whom the Greeks had abandoned for 10 years on Lemnos, was required, by oracular mandate, in order for the Greeks to win the Trojan War.
Hercules asked help from the gods to end his life and received it. Jupiter sent lightning to consume Hercules' mortal body and took Hercules to live with the gods on Mt. Olympus (the apotheosis or, in other words, the turning of Hercules into a god).
Hercules and Hera Reconcile
Although the queen of the gods, Juno or Hera, had been the bane of Hercules' earthly existence, once he was made a god, Juno was reconciled to her stepson and even gave him her daughter Hebe for his divine wife.
