Rescue opera was primarily a product of the French Revolution. The social changes of the period meant that opera must now appeal to the masses, and post-aristocratic, patriotic, idealistic themes—such as resistance to oppression, secularism, the political power of individuals and of people working together, and fundamental changes to the status quo—were popular. The Terror influenced stories of fear and imprisonment; a number of plots, including that of "Fidelio" and other operas based on the same libretto as well as that of "Les deux journées", were taken from real life.