Georg Friedrich Bernhard Riemann (September 17, 1826 – July 20, 1866) was an influential German mathematician who made very important contributions to analysis and differential geometry, some of them helping the later development of general relativity.
Riemann's written works opened up research areas combining analysis with geometry. These would later become big parts of the theories of Riemannian geometry, complex manifold theory, and algebraic geometry. He also made a lot of contributions to real analysis and developed a theory of trigonometric series. His work on monodromy and the hypergeometric function made a big impact too.
