I watched this streaming by the New York Metropolitan Opera company two nights ago and found it to be excellent.
Set in ancient Egypt, the story begins with Aida, an Ethiopian who had been captured in an earlier war between her country and Egypt, who is now a slave in the service of Amneris, the daughter of the pharaoh. She keeps secret from everyone that she is really the daughter of the Ethiopian king Amonasro. She and an Egyptian soldier Radames fall in love but then he is appointed commander of the Egyptian forces to challenge the Ethiopian forces who have regrouped and are invading Egypt. Aida is torn between her love for Radames and her desire to have her own nation not be defeated in war.