A god of healing, (spelled Παιήων) is mentioned twice in the Iliad. In book 5, the Olympian god of war Ares is wounded by mortal hero Diomedes, who is assisted by Athena. Ares is taken up to Olympus in a hurry, where Paeon applies medicine (φάρμακα) that produced an instant relief.Hades too had a similar medical treatment by Paeon when he was shot with an arrow by Heracles. In the Odyssey, Homer says of Egypt:
"... there the earth, the giver of grain, bears greatest store of drugs, many that are healing when mixed, and many that are baneful; there every man is a physician, wise above human kind; for they are of the race of Paeeon."
Hesiod identifies Paeon as an individual deity:
"Unless Phoebus Apollo should save him from death, or Paean himself who knows the remedies for all things."
In time, Paeon (more usually spelled Paean) became an epithet of Apollo, in his capacity as a god capable of bringing disease and therefore propitiated as a god of healing. Later, Paeon becomes an epithet of Asclepius, the healer-god.