Mathematical equations. Coloured image of part of a page of a manuscript written by the French mathematician Evariste Galois (1811-1832). Galois worked on elliptical integrals and the theory of the solutions of equations. His work was largely unrecognised during his life, although he had several papers published before the age of 16. Much of his work was contained in a letter to a former schoolmaster, which he wrote on the night before he died in a dual, aged just 20. Galois is considered one of the founders of modern group theory.