found: Wikipedia, 26 April 2017(Léon Halévy; Léon Halévy (4 January 1802-2 September 1883) was a French civil servent, historian and dramatist; born to a Jewish family in Paris, Léon was the son of the writer and chazzan Élie Halévy and the younger brother of the composer Jacques François Fromenthal Halévy; he married the daughter of the architect Louis-Hippolyte Lebas; their son Ludovic Halévy was one of the leading librettists of mid-century France; Ludovic's own children, Élie Halévy and Daniel Halévy, were noted academics; another son, by Léon's liaison with an opera singer, was the politician Lucien-Anatole Prévost-Paradol; he died, aged 81, at Saint Germain-en-Laye)
