LYON-CAEN, CHARLES LÉON (1843–1935), French jurist. The son of a tailor, Lyon-Caen spent some time on his father's business before studying law. His doctoral thesis, Partagesd'ascendants (1867), earned him a considerable reputation as a jurist and he became professor of law at the Sorbonne in 1872, a post he held for nearly half a century. Lyon-Caen was an authority on commercial and international law and was the author of important works on both subjects. His Precis de droit commercial (2 vols., 1885) and Traité de droit commercial (8 vols., 1885), written with Louis Renault, became standard works, while his Droit international privé maritime (1883) was one of the first textbooks on maritime law as a separate branch of the law. His other works include De la condition légale des sociétes étrangères en France (1870). Lyon-Caen was elected to the Académie des sciences morales et politiques in 1884 and became its permanent secretary in 1893. He was active in Jewish affairs as president of L'œuvre des orphelins Israélites and the Comité d'aide aux émigrants juifs.