The poet invokes a muse to aid him in telling the story of the rage of Achilles, the greatest Greek hero to fight in the Trojan War. The narrative begins nine years after the start of the war, as the Achaeans sack a Trojan-allied town and capture two beautiful maidens, Chryseis and Briseis. Agamemnon, commander-in-chief of the Achaean army, takes Chryseis as his prize. Achilles, one of the Achaeans’ most valuable warriors, claims Briseis. Chryseis’s father, a man named Chryses who serves as a priest of the god Apollo, begs Agamemnon to return his daughter and offers to pay an enormous ransom. When Agamemnon refuses, Chryses prays to Apollo for help.

Apollo sends a plague upon the Greek camp, causing the death of many soldiers. After ten days of suffering, Achilles calls an assembly of the Achaean army and asks for a soothsayer to reveal the cause of the plague. Calchas, a powerful seer, stands up and offers his services. Though he fears retribution from Agamemnon, Calchas reveals the plague as a vengeful and strategic move by Chryses and Apollo. Agamemnon flies into a rage and says that he will return Chryseis only if Achilles gives him Briseis as compensation.

Agamemnon’s demand humiliates and infuriates the proud Achilles. The men argue, and Achilles threatens to withdraw from battle and take his people, the Myrmidons, back home to Phthia. Agamemnon threatens to go to Achilles’ tent in the army’s camp and take Briseis himself. Achilles stands poised to draw his sword and kill the Achaean commander when the goddess Athena, sent by Hera, the queen of the gods, appears to him and checks his anger. Athena’s guidance, along with a speech by the wise advisor Nestor, finally succeeds in preventing the duel.

That night, Agamemnon puts Chryseis on a ship back to her father and sends heralds to have Briseis escorted from Achilles’ tent. Achilles prays to his mother, the sea-nymph Thetis, to ask Zeus, king of the gods, to punish the Achaeans. He relates to her the tale of his quarrel with Agamemnon, and she promises to take the matter up with Zeus—who owes her a favor—as soon as he returns from a thirteen-day period of feasting with the Aethiopians. Meanwhile, the Achaean commander Odysseus is navigating the ship that Chryseis has boarded. When he lands, he returns the maiden and makes sacrifices to Apollo. Chryses, overjoyed to see his daughter, prays to the god to lift the plague from the Achaean camp. Apollo acknowledges his prayer, and Odysseus returns to his comrades.

But the end of the plague on the Achaeans only marks the beginning of worse suffering. Ever since his quarrel with Agamemnon, Achilles has refused to participate in battle, and, after twelve days, Thetis makes her appeal to Zeus, as promised. Zeus is reluctant to help the Trojans, for his wife, Hera, favors the Greeks, but he finally agrees. Hera becomes livid when she discovers that Zeus is helping the Trojans, but her son Hephaestus persuades her not to plunge the gods into conflict over the mortals.

Like other ancient epic poems, the Iliad presents its subject clearly from the outset. Indeed, the poem names its focus in its opening word: menin, or “rage.” Specifically, the Iliad concerns itself with the rage of Achilles—how it begins, how it cripples the Achaean army, and how it finally becomes redirected toward the Trojans. Although the Trojan War as a whole figures prominently in the work, this larger conflict ultimately provides the text with background rather than subject matter. By the time Achilles and Agamemnon enter their quarrel, the Trojan War has been going on for nearly ten years. Achilles’ absence from battle, on the other hand, lasts only a matter of days, and the epic ends soon after his return. The poem describes neither the origins nor the end of the war that frames Achilles’ wrath. Instead, it scrutinizes the origins and the end of this wrath, thus narrowing the scope of the poem from a larger conflict between warring peoples to a smaller one between warring individuals.

But while the poem focuses most centrally on the rage of a mortal, it also concerns itself greatly with the motivations and actions of the gods. Even before Homer describes the quarrel between Achilles and Agamemnon, he explains that Apollo was responsible for the conflict. In general, the gods in the poem participate in mortal affairs in two ways. First, they act as external forces upon the course of events, as when Apollo sends the plague upon the Achaean army. Second, they represent internal forces acting on individuals, as when Athena, the goddess of wisdom, prevents Achilles from abandoning all reason and persuades him to cut Agamemnon with words and insults rather than his sword. But while the gods serve a serious function in partially determining grave matters of peace and violence, life and death, they also serve one final function—that of comic relief. Their intrigues, double-dealings, and inane squabbles often appear humorously petty in comparison with the wholesale slaughter that pervades the mortal realm. The bickering between Zeus and Hera, for example, provides a much lighter parallel to the heated exchange between Agamemnon and Achilles.

Indeed, in their submission to base appetites and shallow grudges, the gods of the Iliad often seem more prone to human folly than the human characters themselves. Zeus promises to help the Trojans not out of any profound moral consideration but rather because he owes Thetis a favor. Similarly, his hesitation in making this promise stems not from some worthy desire to let fate play itself out but from his fear of annoying his wife. When Hera does indeed become annoyed, Zeus is able to silence her only by threatening to strangle her. Such instances of partisanship, hurt feelings, and domestic strife, common among the gods of the Iliad, portray the gods and goddesses as less invincible and imperturbable than we might imagine them to be. We expect these sorts of excessive sensitivities and occasionally dysfunctional relationships of the human characters but not the divine ones.

The clash between Achilles and Agamemnon highlights one of the most dominant aspects of the ancient Greek value system: the vital importance of personal honor. Both Agamemnon and Achilles prioritize their respective individual glories over the well-being of the Achaean forces. Agamemnon believes that, as chief of the Achaean forces, he deserves the highest available prize—Briseis—and is thus willing to antagonize Achilles, the most crucial Achaean warrior, to secure what he believes is properly owed to him. Achilles would rather defend his claim to Briseis, his personal spoil of victory and thus what he believes is properly owed to him, than defuse the situation. Each man considers deferring to the other a humiliation rather than an act of honor or duty; each thus puts his own interest ahead of that of his people, jeopardizing the war effort.