Family Edit
Augustin-Jean Fresnel (also called Augustin Jean or simply Augustin), born in Broglie, Normandy, on 10*May 1788, was the second of four sons of the architect Jacques Fresnel (1755–1805)[10] and his wife Augustine, née Mérimée (1755–1833).[11] In 1790, following the Revolution, Broglie became part of the département of Eure. The family moved twice — in 1790 to Cherbourg,[12] and in 1794[13] to Jacques' home town of Mathieu, where Madame Fresnel would spend 25 years as a widow,[14] outliving two of her sons.

The first son, Louis (1786–1809), was admitted to the École Polytechnique, became a lieutenant in the artillery, and was killed in action at Jaca, Spain, the day before his 23rd birthday.[11] The third, Léonor (1790–1869),[10] followed Augustin into civil engineering, succeeded him as Secretary of the Lighthouse Commission,[15] and helped to edit his collected works.[16] The fourth, Fulgence Fresnel (1795–1855), became a noted linguist, diplomat, and orientalist, and occasionally assisted Augustin with negotiations.[17] Léonor apparently was the only one of the four who married.[11][18]

Their mother's younger brother, Jean François "Léonor" Mérimée (1757–1836),[11] father of the writer Prosper Mérimée (1803–1870), was a paint*artist who turned his attention to the chemistry of painting. He became the Permanent Secretary of the École des Beaux-Arts and (until 1814) a professor at the École Polytechnique,[19] and was the initial point of contact between Augustin and the leading optical physicists of the day (see below).