At the surface Nabucco is a story of two (half) sisters who are in love with the same man. He Ismaele, a Jewish man and nephew of the king of Jerusalem, is the former ambassador of Jerusalem in Babylonia and returned home because of the aggression of Babylonia against Jerusalem. The two (half) sisters, Abigaille (supposedly the elder daughter) and Fenena) are the ‘daughters’ of Nabucco, the king of Babylonia and the one who declared war against Jerusalem.
The underlining story of the opera tells is also the inevitability of fate predicted by the four prophecies of Jeremiah affixed by the librettist at the beginning of each act: ‘punishment; exile; expiation and, finally, the new alliance’. It is in other words a story of the power of God. ‘He’ is angered by his people in Jerusalem because they have lost fate in him and that’s why Nabucco is able to overtake Jerusalem (punishment). Nabucco take the men and women from Jerusalem as slave to Babylonia (exile). There the high priest of the Jews exhorts them to have faith: God will destroy Babylon (expiation). Nabucco meanwhile is taken prisoner by Abigaille after he lost his mind, declaring himself ‘Dio’.