Persians is the earliest extant Greek tragedy and the only one to be based on a historical rather than a mythical incident: the victory of the Greeks at the sea battle of Salamis in 480 bc, in which Aeschylus himself took part. It formed the central piece of a trilogy, possibly following one about the Battle of Marathon (in 490 bc) and preceding one that celebrated the Athenian victory. As it stands, we have a remarkable piece that, far from being a jingoistic celebration of the most decisive victory in Greek history, focuses on the suffering of the vanquished. At the same time, it reflects the Greek tragic view that hubris (pride), as displayed by the great Xerxes, is followed by nemesis (retribution). It offers a warning to the Athenians that they should not themselves now become hubristic, for fear of the consequences. Persians also employed dramatic devices that were to become well used by subsequent writers: the messenger's report and the ghostly apparition.
Related content in Oxford Reference
Aeschylus (525—456 bc) Greek dramatist