In Greek mythology, Chiron ("hand") — sometimes spelled Cheiron or Kiron — was held as the superlative centaur over his brethren. Like the satyrs, centaurs were notorious for being overly indulgent drinkers and carousers, given to violence when intoxicated, and generally uncultured. Chiron, by contrast, was intelligent, civilized and kind. Sired by Cronus when he had taken the form of a horse and impregnated the nymph, Philyra, Chiron came from a different lineage than other centaurs. He was the father of Ocyrrhoe with the nymph Chariklo and lived on Mount Pelion.
A great healer, astrologer, and respected oracle, Chiron was most revered as a teacher and tutored Asclepius, Theseus, Achilles, Jason and Heracles. He had the gift of guiding his pupils to uncovering their highest potential and discovering their destiny. When the centaurs drank and partied themselves to extinction, Chiron became the last remaining centaur. His nobility is further reflected in the story of his death as Chiron sacrificed his life, allowing humanity to obtain the use of fire. Being the son of Cronus, a titan, he was therefore immortal and so could not die. So it was left to Heracles to arrange a bargain with Zeus to exchange Chiron's immortality for the life of Prometheus who had been chained to a rock and left to die for his transgressions. Chiron had been poisoned with an arrow belonging to Heracles that had been treated with the blood of the Lernaean Hydra (in other versions, poison Chiron had given to the hero when he had been under the honorable centaur’s tutelage). This had taken place during the visit of Heracles to the cave of Pholus on Mount Pelion in Thessaly when he visited his friend during his fourth labour in defeating the Erymanthian Boar. While they were at supper, Heracles asked for some wine to accompany his meal. Pholus, who ate his food raw, was taken aback. He had been given a vessel of sacred wine by Dionysus sometime earlier, to be kept in trust for the rest of the centaurs until the right time for its opening. At Heracles's prompting, Pholus was forced to produce the vessel of sacred wine. The hero, gasping for wine, grabbed it from him and forced it open. Thereupon the vapours of the sacred wine wafted out of the cave and intoxicated the wild centaurs, led by Nessus, who had gathered outside. They attacked the cave with stones, rocks and fir trees. Hercules was forced to shoot many arrows (poisoned, of course, with the blood of the Hydra) to drive them back. During this assault, Chiron was hit in the thigh by one of the poisoned arrows. After the centaurs had fled, Pholus emerged from the cave to observe the destruction. Being of a philosophical frame of mind, he pulled one of the arrows from the body of a dead centaur and wondered how could such a little thing as an arrow have caused so much death and destruction? In that instant, he let slip the arrow from his hand and it dropped and hit him in the foot, killing him instantly.
Ironically, Chiron, the master of the healing arts, could not heal himself, so he willingly gave up his immortality and was placed in the sky as the constellation Centaurus.
Chiron saved the life of Peleus when Acastus tried to kill him by taking his sword and leaving him out in the woods to be slaughtered by the centaurs. Chiron retrieved the sword for Peleus. Some sources speculate that Chiron was originally a Thessalian god, later subsumed into the Greek pantheon as a centaur.