Henri Léon Lebesgue 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 at the University of Nancy during 1902.

Beauvais is a town and commune in northern France, and prefecture of the Oise département, in the Hauts-de-France region, 75 kilometres north of Paris.