Hippocrates of Chioswas a Greek merchant turned mathematician who wrote the first textbook on geometry. He is also noted for his efforts in elucidating the properties of circles and the quadrature of the lune. Despite turning to mathematics later in life, Hippocrates, who was also interested in astronomy, has been called the greatest mathematician of the fifth century B.C.

Hippocrates was born on the island of Chios but little else is known about his life. He is not to be confused with the more famous Hippocrates of Cos, who was born in the same century and is known as the father of medicine. According to information passed down by Aristotle, Proclus, Simplicius, and others, Hippocrates' first calling was as a merchant. However, unlike the famous Greek mathematician Thales, who made a fortune in commerce, Hippocrates' endeavors in trade led to his financial ruin.

It is speculated that...