Seeing as the play is named after Agamemnon and all, you'd probably expect us to know a lot about his character, right? Actually, this isn't really true. Even though Agamemnon is the play's "tragic hero" (great man who's cut down to size), he doesn't appear onstage until halfway through the play. Then, he disappears and isn't heard from again. Well, that's not quite true; actually, he's not heard of except for two bloodcurdling cries – but we think anybody who was being murdered would probably act the same way, so they don't really tell us much about his character. So, basically, to understand Agamemnon, we have one scene to go with, plus the reports of other characters. Because these reports are only second hand, we'll have to take them with a grain of salt. All the same, because we first learn about Agamemnon from these reports, let's start with them, and then work our way up to Agamemnon's big scene onstage.
Our earliest picture of Agamemnon comes in the Watchman's speech that opens the play. The Watchman tells us that Agamemnon has been gone for ten years fighting against the Trojans; when he complains that the household isn't managed as well as it used to be, and says he can't wait to shake his master's hand again, this tells us that Agamemnon must be a pretty competent king.
Our picture of Agamemnon becomes more complicated, however, during the first song of the Chorus. The Chorus starts off by saying that Agamemnon and Menelaus were just in making war against the Trojans; in fact, they explicitly say that Agamemnon was sent by Zeus. You can put this information in the "Agamemnon = Good Guy" column. But things get trickier after bad winds keep the Greek fleet at Aulis, and Agamemnon learns from the soothsayer Calchas that the goddess Artemis wants him to sacrifice his daughter, Iphigenia. We mean, sure, Agamemnon found himself in a bad position and all, but did he really have no choice but to slaughter his own daughter? Even though this is kind of ambiguous, were going to put it in the "Agamemnon = Bad Guy" column.
OK, so much for the back-story we get about Agamemnon from other characters. What about how the guy acts when he's actually onstage? Here, once again, we get an ambiguous picture. When Agamemnon first arrives, he makes a big speech about how the gods must be thanked. Basically, he's trying to appear like one pious dude. Then, when Clytemnestra tries to get him to walk on the purple fabrics, he's still in piety mode, saying, "Oh, the gods wouldn't approve of that, I shouldn't do it…" But if Agamemnon's so pious, why does he give in to his wife's bullying? It isn't like her arguments are very convincing – at least they shouldn't be to a sensible person without a huge ego problem. But as soon as she says, "King Priam of Troy would have done it if he had the chance," Agamemnon is like, "Well, I'm sure not going to let him get the last laugh!" (He has apparently forgotten that his soldiers killed Priam the night before.) So, based on this scene, we'd have to say that Agamemnon, despite his claims to piety, is actually pretty arrogant and foolish. What do you think?