[Son] of Kalliphon (a priest of Asklepios born in Knidos); a Krotoniate,[1] a doctor. He practised medicine in Aigina [Myth, Place], where he married, and he also acted as physician to Polykrates, the tyrant of Samos, for two gold talents; and he was summoned by Dareios the Persian and stayed with him for a considerable time. He wrote a medical book.
When Dareios the king was out hunting he twisted his foot while dismounting from his horse, and did so rather violently; for the astragal[2] came out from the joint. He first summoned the Egyptian doctors he had around him, considered to be the foremost, skilled in medical arts. They treated him, but, by twisting and stretching the foot they caused major damage. For seven days and seven nights Dareios could not sleep because of the hurt he was experiencing; but on the eighth day of his affliction someone who had heard, before leaving Sardis, of the skill of Demokedes of Kroton informed Dareios, who ordered [Demokedes] to be brought to him as soon as possible. Finding Demokedes utterly neglected somewhere among Oroetes' slaves, they brought him forward, dragging his chains and dressed in rags. As he stood there on public view, Dareios asked him whether he knew the skill [of a doctor]. Demokedes denied this, fearful that if he revealed himself he would not be able to return to Greece again. It was clear to Dareios that he was trying to trick him by craftiness, and he ordered the men who fetched him to step forward with whips and goads. So then, of course, Demokedes came clean, while maintaining that his learning was imprecise; he had, though, kept company with a physician and thereby picked up some insufficient knowledge of the art. But later Dareios entrusted himself to Demokedes, who with the use of Greek remedies and gentle rather than forcible means -- after such procedures had been tried by others -- succeeded in getting Dareios his sleep and, after a while, healed him completely, though he had lost hope of having the proper use of his foot again. So says Herodotus the historian. [He also says] that Atossa, Kyros' daughter and the wife of Dareios, found an abscess growing in her breast which broke and spread further. As long as it was small, she hid it because of shame and did not tell anyone about it; but when it turned for the worse she sent for Demokedes and showed it to him. He said that he could heal her but made her swear that she would do him any service he asked for in return, saying that he would not ask for anything that was shameful. And what he asked for was his return to Greece.[3]