Lagrange, Joseph Louis, comte de l'Empire (Count of the Empire)[lagrãzh], originally Giuseppe Luigi Lagrangia
Mathematician and astronomer, born in Turin, Italy. In 1766 he became director of the Berlin Academy, and published papers on many aspects of number theory, mechanics, the stability of the Solar System, and algebraic equations. His major work was the Mécanique analytique (1788, Analytical Mechanics), and he was appointed professor of mathematics at the Ecole Polytechnique, heading the committee reforming the metric system (1795). He was made a senator and a count by Napoleon. The Lagrangian point in astronomy, the Lagrangian function in mechanics, and several notions in mathematics are all named after him.