Charles-Julien BrianchonFrench mathematician geometer, was born in Sevres (France) in the year 1783 and died in Versailles (France) in 1864. He published in the Journal de l'E.P (1806) the well-known Brianchon theorem. He entered the Polytechnique School of Paris (1804), where he was a student of Monk.
Your first paper was Sur les surfaces courbes du second degré, in the Journal of l'Ecole Polytechnique, while still a student, about Pascal's magic hexagon. He graduated in 1808 as the first of the class, at the time of Emperor Napoleon Bonaparte, of whose army he was a part, intending to make a military career. However, with health problems, he left military service (1813) in exchange for a teaching post.
Five years later (1818) he became a professor at the Royal Guard Artillery School in Vincennes, where he continued to publish papers such as Recherches on the termination of a hyperbole, with four conditions (1820). Then his interest turned to chemistry, where he was not so successful.