Euclid, coloured woodcut, 1584.The Granger Collection, New York
Euclid, Greek Eukleides   (born c. 300 bceAlexandria,
Egypt), the most prominent mathematician of Greco-Roman
antiquity, best known for his treatise on geometry, the
Elements.   Of Euclid’s life nothing is known except what the
Greek philosopher Proclus (c. 410–485 ce) reports in his
“summary” of famous Greek mathematicians. According to him,
Euclid taught at Alexandria in the time of Ptolemy I Soter, who
reigned over Egypt from 323 to 285 bce. Medieval translators and
editors often confused him with the philosopher Eukleides of
Megara, a contemporary of Plato about a century before, and
therefore called him Megarensis. Proclus supported his date for
Euclid by writing “Ptolemy once asked Euclid if there was not a
shorter road to geometry than through the Elements, and Euclid
replied that there was no royal road to geometry.” Today few
historians challenge the consensus that Euclid was older than
Archimedes (c. 290/280–212/211 bce).  Sources and