Ambroise Thomas (Metz 5 August 1811 - Paris, 12 February 1896) was a French opera composer, best-known for his operas Mignon (1866) and Hamlet (1868, after Shakespeare) and as director of the Conservatoire de Paris from 1871-1896.
http://en.wikipedia.org/wiki/Ambroise_Thomas
https://adp.library.ucsb.edu/names/104369