Riemann, (Georg Friedrich) Bernhard (1826-1866) - Theory of functions, non-Euclidian geometry, relativity theory, His profound conjecture (the Riemann hypothesis) about the behavior of the zeta (or Riemann) function, which he showed determines the distribution of the prime numbers.

Thales of Miletus (c. 624-547 B.C.) - The first named mathematician, famous for his theorems -- circle bisected by diameter; angles at base of isosceles triangle are equal vertically opposed angles are equal.

Apollonius of Perga (c. 262-190 B.C.) - known as 'The Great Geometer', great influence on the development of mathematics, famous book Conics introduced terms such as parabola, ellipse and hyperbola.

Heron of Alexandria (ca. 75 AD) - Greek mathematician who was mainly interested in practical studies in mechanics and engineering, best known for Heron's Formula

Desargues - Girard Desargues (1591-1661) - Founder of projective geometry, his work centred on the theory of conic sections and perspective.

Pappus of Alexandria (c. 320) - Wrote treatise, the Mathematical Collection, as a guide to Greek geometry, discusses theorems and constructions of more than thirty different mathematicians of antiquity.

Klein, Felix (1849-1925) - Plücker's assistant at Bonn who studied Analytic Geometry, describing geometry as the study of properties of figures which remain invariant under a Group of Transformations. He systemized Non-Euclidean Geometry.

Monge - Gaspard Monge, Conte de Péluse (1746-1818) - The father of differential geometry, he devised a system called Geometrie descriptive, now known as orthographic projection, the graphical method used in modern mechanical drawing.