325?-250? B.C.

Greek Mathematician

Euclid's Elements, the bible of geometry for 2,000 years, remains the most influential textbook in history, and one of the essential works of human civilization. Therefore it is all the more ironic that the man who wrote it is such a figure of mystery that at various times historians have suggested that he never lived—or that "Euclid" was actually the name for a group of mathematicians.

In fact the historical existence of a man named Euclid of Alexandria, author of the Elements, seems safely established. Most of what scholars know about his life, however, comes from a short summary in Proclus's (410?-485) commentary on the Elements. As for his place of origin, this has been variously identified as Tyre (now in Lebanon), Greece, or Egypt, with the last two being the most likely candidates. Whatever the case, he was almost without a doubt...