Thais is an opera in three acts by Jules Massenet based on a novel of the same name. The opera was first produced at the Opera in Paris in 1894. The work is set in Roman Egypt and tells the story of a Cenobite monk, Athanael, who attempts to covert Thais, a courtesan of Alexandria, to Christianity, but discovers, too late, that his obsession with her is rooted in lust. It has been described as bearing a kind of religious eroticism and has spawned many controversial productions.