Opera in four acts

Libretto by Antonio Ghislanzoni

Egypt, during the reign of the Pharaohs

ACT I: In the antechamber of the royal palace at Memphis, Radames, a young captain of the guard, asks the high priest Ramfis if the goddess Isis has chosen a new commander to lead the Egyptian forces against the Ethiopians. Left alone, Radames hopes that he is the chosen one, imaging a glorious victory so he may free his beloved Aida, slave of Amneris, who is the King's daughter ("Celeste Aida"). Amneris, who loves Radames, interrupts his musing and questions him; her suspicion that he loves Aida increases at the entrance of her slave girl (Trio: "Vieni, o diletta"). In the throne room, the King gives audience to a messenger from the front, who reports that the Ethiopian army, led by Amonasro, is marching on Thebes. The King announces the appointment of radame as Egyptian commander and leads the assemblage in a battle hymn. As Radames is led off amid general rejoicing, Aida remains alone, appalled that she too has cheered him to victory ("Ritorna vincitor!"), for the Ethiopians are her people, and Amonasro, their king, is her father. Torn by conflicting loyalties, she begs the gods for pity.

In the temple of Ptah, a priestess is heard addressing the god as radames is ceremonially clothed in the sacred armor and consecrated to the service of the god. All present invoke Ptah's guidance and protection for the army.