Georg Friedrich Bernhard Riemann (September 17, 1826 - July 20, 1866) was a German mathematician who made lasting contributions to analysis, number theory, and differential geometry, some of them enabling the later development of general relativity. His teachers were amazed by his adept ability to perform complicated mathematical operations, in which he often outstripped his instructor's knowledge. In 1846, at the age of 19, he started studying philology and theology at the University of Gottingenin. He also began studying mathematics under Carl Friedrich Gauss who recommended the give up his theological work and enter the mathematical field. He held his first lectures in 1854, which founded the field of Riemannian geometry and thereby set the stage for Einstein's general theory of relativity. He died of tuberculosis in 1866 at the age of 39. His published works opened up research areas combining analysis with geometry. These would subsequently become major parts of the theories of Riemannian geometry, algebraic geometry, and complex manifold theory.