There is wind of war in Memphis. Ramfis, the High Priest and secret power of the State, informs Radames, captain of the guards, that the Ethiopians are about to invade Egypt. The idea of a war stimulates Radames, a man of ambition and courage. He hopes the god Isis will appoint him supreme commander of the army. He dreams of glory, and everything seems possible. War, for him, is also an occasion to appear valiant before the eyes of the woman he secretly loves: Aida, an Ethiopian slave in the service of Amneris, the Pharaoh’s daughter.
The Egyptian princess is also in love with Radames. Intuitive by nature, though, she immediately suspects she has a rival in this slave but prefers to conceal her jealousy with double cunning. Meanwhile, Aida’s heart is heavy with anxiety: her country is at war, yet at the same time, a love links her to a new world.
A fanfare sounds and a majestic choral scene overrides individual conflicts and aspirations. The leaders of the State meet to plan a war strategy. The King and Ramfis stand out as personalities who have no individual identity, personifying a power which crushes anyone who stands in their way.