Hippocrates of Chios (Greek: Ἱπποκράτης ὁ Χῖος) was an ancient Greek mathematician, geometer, and astronomer, who lived c. 470 – c. 410 BCE.He was born on the isle of Chios, where he originally was a merchant. After some misadventures (he was robbed by either pirates or fraudulent customs officials) he went to Athens, possibly for litigation. There he grew into a leading mathematician.On Chios, Hippocrates may have been a pupil of the mathematician and astronomer Oenopides of Chios.