Saint-Saens began the composition of "Samson et Dalila" in 1869.

The author of the book, Ferdinand Lemaire, was a cousin of the composer.

Before the breaking out of the Franco-Prussian War the score was so far on the way to completion that it was possible to give its second act a private trial.
This was done, an incident of the occasion-which afterward introduced one element of pathos in its history-being the singing of the part of Samson by the painter Henri Regnault, who soon after lost his life in the service of his country.

A memorial to him and the friendship which existed between him and the composer is the "Marche Heroique," which bears the dead man's name on its title-page.

Toward the end of 1872 the opera was finished.