Augustin-Louis Cauchy was a French mathematician. He was famous for the countless contributions he made to the domain of mathematics. He made special contribution to mathematical analysis and the theory of substitution groups. For a brief period, he served as a military engineer for Napoleon’s English invasion fleet. He wrote many books that cover a wide area of mathematics and mathematical physics. He authored around eight hundred research articles. His paper on definite integrals acted as the basis of the theory of complex functions. Due to his praiseworthy contribution to wave propagation , which is an important part of hydrodynamics, he received the prestigious grand prix from the Institute of France. His theories on functions of complex variables have played substantial part in subjects ranging from applied mathematics to aeronautics. His significant papers on error theory act as valuable asset for the domain of science. Cauchy was the first mathematician who developed definitions and rules for mathematics. He introduced the definitions of the integral and rules for series convergence. As a person he was a God-fearing, earnest Roman Catholic and a strict Bourbon royalist. He was actively involved with Institut Catholoque and Ecole Normale Ecclesiastique.