Augustin-Louis Cauchy
Augustin-Louis Cauchy (21 August 1789 – 23 May 1857) was a French mathematician and physicist who made many important contributions to mathematical analysis and mathematical physics, including elasticity. Importantly, he created complex analysis, which studies complex functions and their properties. Cauchy graduated the École Polytechnique and École des Ponts ParisTech. Cauchy did not like mathematicians making assumptions, and he particularly did not like the way that earlier mathematicians, such as Euler and Lagrange, assumed that properties of finite expansions, meaning that we can count the number of terms, also worked for infinite series. Cauchy was able to give examples of where this did not work, and called the assumptions that the earlier mathematicians made, the generality of algebra. More theorems have been named after Cauchy than any other mathematician in history.