Of the four included in this volume, The Persians is unique in Greek tragedy in having as its subject matter a recent historical event, the defeat of the Persians at the famous battle of Salamis. The other three, Prometheus, The Suppliants and Seven Against Thebes, were all written as parts of trilogies and take their themes from Greek legend, but in each Aeschylus' interpretation reflects the new morality of classical Athens. Thus, in Seven Against Thebes the fate of the two main figures, Eteocles and Polyneices, is not entirely controlled by the gods, for Eteocles is free to choose whether or not he should fight his brother. And in Prometheus and The Suppliants Aeschylus shows that although the struggle of reason against violence can never be an easy one, it is reason that is the proper principle of civilized life.