Biografia   

Georges Hartmann (15 May 1843, Paris - May 1900, Paris) was a French dramatist and opera librettist who wrote under the pen name Henri Grémont.
Since 1870 he was also a music publisher, publishing compositions of Jules Massenet. In May 1891 his publishing house failed and he was forced to sell it to Henri Heugel[1] which, subsequently (through merger in 1980), became part of Alphonse Leduc[2][3] publishing empire.
Hartmann's librettos include Massenet's Hérodiade (1881) and Werther (1892), Silver's "Château Brillon" (1892), André Messager's Madame Chrysanthème (1893) and Reynaldo Hahn's L'Île du rêve (1898).

fonte: wikipedia

fonte: data.bnf.fr/16557205/henri_gremont/