Lagrange (1736-1813): a life in mathematics

We retrace the scientific biography of Joseph-Louis Lagrange, entirely dedicated to the study of mathematics, from the time when, still adolescent, he abandoned the studies of law which were a family tradition. His existence was divided almost equally into three periods: Turin (1736–1766) where he was born and composed his first fundamental memoirs on vibrating strings and the calculus of variations; Berlin (1766–1787) at the Academy of Frederick II of Prussia, where he published many works and drafted his 'Méchanique analitique'; and Paris (1787–1813), during the time of the French Revolution and the Napoleonic Empire, where he published his treatises and received the highest honours. Here we present the few significant events of his private life and the many results with which he enriched almost all the mathematical sciences.