Henri Poincare (1854-1912). Caricature of the French mathematician Jules Henri Poincare. Henri Poincare is considered one of the greatest mathematicians of all time. He is said to have been the last of the universal mathematicians, as he managed leading work in all branches of the subject. He gained his doctorate in 1879, working on celestial mechanics at Paris. He made major contributions to the 'three-body' problem, calculating the mutual gravitational effects of three orbiting bodies. He also worked on the theory of tides and rotating fluid spheres. Other work included topology and relativity, and Poincare is considered the founder of chaos theory.