Henri Lebesgue (1875–1941)
Born 1875 CE, died 1941 CE.
Henri Léon Lebesgue (; French: [ɑ̃ʁi leɔ̃ ləbɛɡ]; June 28, 1875 – July 26, 1941) was a French mathematician known for his theory of integration, which was a generalization of the 17th-century concept of integration—summing the area between an axis and the curve of a function defined for that axis. His theory was published originally in his dissertation Intégrale, longueur, aire ("Integral, length, area") at the University of Nancy during 1902.
Text from the Wikipedia article Henri_Lebesgue, licensed CC BY-SA 4.0.