Klein, (Christian) Felix[kliyn]
Mathematician, born in Düsseldorf, Germany. He studied at the University of Bonn, and held chairs at Erlangen (1872--5), Munich (1875--80), Leipzig (1880--6), and Göttingen (1886--1913). He worked on geometry, including non-Euclidean geometry, function theory (in which he developed Bernhard Riemann's ideas), and elliptic modular and automorphic functions. His Erlanger Programm showed how different geometries could be classified in terms of group theory. He also wrote on the history of mathematics, encouraged links between pure and applied mathematics and engineering, and promoted general mathematical education.