Évariste Galois, the founder of Galois theory and group theory, was an early student at ENS, then still called École préparatoire, in the 1820s, at the same time as fellow mathematician Augustin Cournot. Though mathematics continued to be taught at the school throughout the 19th century, its real dominance of the mathematic sphere would not emerge until after the First World War, with a young generation of mathematicians led by André Weil, known for his foundational work in number theory and algebraic geometry (also the brother of fellow student, philosopher Simone Weil). This rejuvenation continued into the 1930s, as exemplified by the 1935 launch of the influential Nicolas Bourbaki project, whose work permeated the field of mathematics throughout the 20th century. In 1940 former student Henri Cartan was appointed professor at the school like his father Élie Cartan, carrying the school's importance in the field still further with his work in algebraic topology. His teaching, which continued until 1965, was vastly influential in shaping his students, who included Yvonne Bruhat, Gustave Choquet, Jacques Dixmier, Roger Godement, René Thom and Jean-Pierre Serre.