Chiron was known for his exceptional goodness and wisdom. He became the tutor for a number of famous Greek heroes including: Achilles, Aesculapius, Actaeon.
Chiron was the only immortal centaur but despite his immortality he was to end up dying. It happened like this:
Hercules visited King Pholus, who held a feast in his honour. Pholus ran out of wine and as Hercules was still thirsty he persuaded Pholus to send men into the forest and steal jars of wine that were the common property of the centaurs. When the jars of wine were opened the centaurs smelled their wine and came running. A fight broke out between Hercules and the centaurs.
Chiron took no part in the fight but, was accidentally wounded by Hercules. As an immortal Chiron could not die but, lived in terrible pain. Chiron then chose to trade his life for the release of Prometheus.