Joseph-Louis Lagrange (January 25, 1736 - April 10, 1813), born Giuseppe Luigi Lagrancia, was an Italian-born French mathematician and astronomer. He made significant contributions to all fields of analysis, number theory, and classical and celestial mechanics. In 1766 he became director of mathematics at the Prussian Academy of Sciences in Berlin, where he stayed for over twenty years, producing a large body of work and winning several prizes of the French Academy of Sciences. Lagrange's parents were Italian, although his paternal great grandfather was French. In 1787, at age 51, he moved from Berlin to France and became a member of the French Academy. He remained in France until the end of his life. Therefore, Lagrange is alternatively considered a French and an Italian scientist. Lagrange survived the French Revolution and became the first professor of analysis at the ?cole Polytechnique upon its opening in 1794. Lagrange was appointed Senator in 1799, and Napoleon named him to the Legion of Honour in 1803 and made him a Count of the Empire in 1808. He died in 1813 at the age of 77. He is buried in the Panth矇on and his name appears as one of the 72 names inscribed on the Eiffel Tower.