Set during the reign of Nebuchadnezzar (Nabucco), King of Babylon, the opera tells the tale of Nabucco's fictitious daughters, Abigaille and Fenena, who are rivals for the love of Ismaele, nephew of the King of Jerusalem.

France, 1792. Chenier is an idealistic poet, in love with the aristocratic Maddalena. While Chenier supports such notions as "liberte, fraternite egalite," his sympathies do not extend to the current Reign of Terror. Likewise, the Revolutionary Tribunal has no need for poets or their girlfriends, especially those judged to be an Enemy of the State. Heads will roll.