What theatrical innovation did the playwright aeschylus come up with?

The theatrical innovation that Aeschylus is most famous for is the introduction of a second actor to the stage.

Before Aeschylus, Greek plays were performed with only a single actor who would interact with a chorus. Aeschylus's innovation allowed for dialogue and conflict between characters, creating a more complex and engaging narrative.

This simple change significantly enriched the possibilities of dramatic storytelling and laid the foundation for the development of the modern play.