Complex sentence: He then was managing director of the Théâtre des Variétés from 1869 to 1891 and director of the Opéra Garnier from 1 January 1892 until his death in 1899, first in association with Campocasso, and then from 1894, with Pedro Gailhard.
Split into simpler sentences: He then was managing director of the Théâtre des Variétés from 1869 to 1891. He was director of the Opéra Garnier from 1 January 1892 until his death in 1899, first in association with Campocasso, and then from 1894, with Pedro Gailhard.