Jules Henri Poincar矇 (April 29, 1854 - July 17, 1912) was a French mathematician, theoretical physicist, engineer, and a philosopher of science. He is often described as a polymath, and in mathematics as The Last Universalist, since he excelled in all fields of the discipline as it existed during his lifetime. He made many contributions to different fields of pure and applied mathematics such as: celestial mechanics, fluid mechanics, optics, electricity, telegraphy, capillarity, elasticity, thermodynamics, potential theory, quantum theory, theory of relativity and physical cosmology. He became the first person to discover a chaotic deterministic system which laid the foundations of modern chaos theory. He is also considered to be one of the founders of the field of topology. He made clear the importance of paying attention to the invariance of laws of physics under different transformations, and was the first to present the Lorentz transformations in their modern symmetrical form. He was also a popularizer of mathematics and physics and wrote several books for the lay public. He was raised in the Roman Catholic faith. However, he rejected Christianity in later life and became an atheist. In 1912, he underwent surgery for a prostate problem and subsequently died from an embolism in 1912 at the age of 58.