Joseph Louis Lagrange (1736 - 1813) was a Franco-Italian mathematician and astronomer. Son of a civil servant, was born in Turin, Italy. Although his father wanted him to be a lawyer, Lagrange was drawn to mathematics and astronomy after reading a paper by astronomer Halley.
At sixteen he began to study mathematics on his own, and at nineteen he was assigned to a teaching post at the Royal Artillery School in Turin. The following year, Lagrange sent Euler solutions to some famous problems using new methods that eventually flourished with a branch of mathematics called Calculus of Variations.
At twenty-five he was considered by many of his contemporaries to be the greatest living mathematician.
In 1776, on Euler's recommendations, he was chosen as his successor, assuming the post of director of the Berlin Academy. After twenty years in Berlin, he moved to Paris at the invitation of Louis XVI, where he devoted himself essentially to didactic treatises that summarized the conception of mathematics.
Your family has always lived modestly. Lagrange himself reported that if his family had money, he would not have followed his vocation, mathematics. Despite his fame, he was always a shy and modest man. After his death in 1813, he was buried with honors in the Pantheon.