Euclid, Greek mathematician, c 275 BC.
© Science Museum / Science & Society Picture Library
(Medieval?) engraving of Euclid (330-275 BC) who lived in Alexandria, Egypt. Little is known about him, although his contribution to mathematics has been a major influence for over 2,000 years. He wrote 'Elements of Geometry' which incorporated previous works in mathematics as well as Euclid's own findings. The writings deal with plane geometry; solid geometry, including the five Platonic solids; and the theory of numbers, including a proof that there are an infinite number of primes. It was not until the 19th century that mathematicians realised other kinds of geometry exist. His achievements are impresive, given that there was little algebra or arithmetic at the time, and limited understanding of infinity. Euclid is shown drawing geometrical shapes.