- Note: Book numbers are in parentheses and come before the synopsis of the book.
(1) After an invocation to the Muses, the story launches in medias res towards the end of the Trojan War between the Trojans and the besieging Greeks. Chryses, a Trojan priest of Apollo, offers the Greeks wealth for the return of his daughter Chryseis, held captive by Agamemnon, the Greek leader. Although most of the Greek army is in favour of the offer, Agamemnon refuses. Chryses prays for Apollo's help, and Apollo causes a plague to afflict the Greek army.
After nine days of plague, Achilles, the leader of the Myrmidon contingent, calls an assembly to deal with the problem. Under pressure, Agamemnon agrees to return Chryseis to her father, but decides to take Achilles' captive, Briseis, as compensation. Achilles furiously declares that he and his men will no longer fight for Agamemnon and will go home. Odysseus takes a ship and returns Chryseis to her father, whereupon Apollo ends the plague.
In the meantime, Agamemnon's messengers take Briseis away. Achilles becomes very upset, sits by the seashore, and prays to his mother, Thetis. Achilles asks his mother to ask Zeus to bring the Greeks to the breaking point by the Trojans, so Agamemnon will realize how much the Greeks need Achilles. Thetis does so, and Zeus agrees.
(2) Zeus sends a dream to Agamemnon, urging him to attack Troy. Agamemnon heeds the dream but first decides to test the Greek army's morale, by telling them to go home. The plan backfires, and only the intervention of Odysseus, inspired by Athena, stops a rout.
Odysseus confronts and beats Thersites, a common soldier who voices discontent about fighting Agamemnon's war. After a meal, the Greeks deploy in companies upon the Trojan plain. The poet takes the opportunity to describe the provenance of each Greek contingent.
When news of the Greek deployment reaches King Priam, the Trojans respond in a sortie upon the plain. In a list similar to that for the Greeks, the poet describes the Trojans and their allies.
(3) The armies approach each other, but before they meet, Paris offers to end the war by fighting a duel with Menelaus, urged by his brother and head of the Trojan army, Hector. The initial cause of the entire war is alluded to here, when Helen is said to be "embroidering the struggles between Trojans and Greeks, that Ares had made them fight for her sake." This allusion is then made definitive at the paragraph's close, when Helen is told that Paris and "Menelaus are going to fight about yourself, and you are to be the wife of him who is the victor." Both sides swear a truce and promise to abide by the outcome of the duel. Paris is beaten, but Aphrodite rescues him and leads him to bed with Helen before Menelaus can kill him.
(4) Pressured by Hera's hatred of Troy, Zeus arranges for the Trojan Pandaros to break the truce by wounding Menelaus with an arrow. Agamemnon rouses the Greeks, and battle is joined.
(5) In the fighting, Diomedes kills many Trojans, including Pandaros, and defeats Aeneas, whom Aphrodite rescues, but Diomedes attacks and wounds the goddess. Apollo faces Diomedes and warns him against warring with gods. Many heroes and commanders join in, including Hector, and the gods supporting each side try to influence the battle. Emboldened by Athena, Diomedes wounds Ares and puts him out of action.
(6) Hector rallies the Trojans and prevents a rout; the Greek Diomedes and the Trojan Glaukos find common ground and exchange unequal gifts. Hector enters the city, urges prayers and sacrifices, incites Paris to battle, bids his wife Andromache and son Astyanax farewell on the city walls, and rejoins the battle.
(7) Hector duels with Ajax, but nightfall interrupts the fight, and both sides retire. The Greeks agree to burn their dead, and build a wall to protect their ships and camp, while the Trojans quarrel about returning Helen. Paris offers to return the treasure he took and give further wealth as compensation, but not Helen, and the offer is refused. A day's truce is agreed for burning the dead, during which the Greeks also build their wall and a trench.
(8) The next morning, Zeus prohibits the gods from interfering, and fighting begins anew. The Trojans prevail and force the Greeks back to their wall, while Hera and Athena are forbidden to help. Night falls before the Trojans can assail the Greek wall. They camp in the field to attack at first light, and their watchfires light the plain like stars.
(9) Meanwhile, the Greeks are desperate. Agamemnon admits his error, and sends an embassy composed of Odysseus, Ajax, Phoenix, and two heralds to offer Briseis and extensive gifts to Achilles, who has been camped next to his ships throughout, if only he will return to the fighting. Achilles and his companion Patroclus receive the embassy well, but Achilles angrily refuses Agamemnon's offer and declares that he would only return to battle if the Trojans reached his ships and threatened them with fire. The embassy returns empty-handed.
(10) Later that night, Odysseus and Diomedes venture out to the Trojan lines, kill the Trojan Dolon, and wreak havoc in the camps of some Thracian allies of Troy's.
(11) In the morning, the fighting is fierce, and Agamemnon, Diomedes, and Odysseus are all wounded. Achilles sends Patroclus from his camp to inquire about the Greek casualties, and while there Patroclus is moved to pity by a speech of Nestor's.
(12) The Trojans attack the Greek wall on foot. Hector, ignoring an omen, leads the terrible fighting. The Greeks are overwhelmed and routed, the wall's gate is broken, and Hector charges in.
(13) Many fall on both sides. The Trojan seer Polydamas urges Hector to fall back and warns him about Achilles, but is ignored.
(14) Hera seduces Zeus and lures him to sleep, allowing Poseidon to help the Greeks, and the Trojans are driven back onto the plain.
(15) Zeus awakes and is enraged by Poseidon's intervention. Against the mounting discontent of the Greek-supporting gods, Zeus sends Apollo to aid the Trojans, who once again breach the wall, and the battle reaches the ships.
(16) Patroclus cannot stand to watch any longer and begs Achilles to be allowed to defend the ships. Achilles relents and lends Patroclus his armor, but sends him off with a stern admonition not to pursue the Trojans, lest he take Achilles' glory. Patroclus leads the Myrmidons into battle and arrives as the Trojans set fire to the first ships. The Trojans are routed by the sudden onslaught, and Patroclus begins his assault by killing Zeus's son Sarpedon, a leading ally of the Trojans. Patroclus, ignoring Achilles' command, pursues and reaches the gates of Troy, where Apollo himself stops him. Patroclus is set upon by Apollo and Euphorbos, and is finally killed by Hector.
(17) Hector takes Achilles' armor from the fallen Patroclus, but fighting develops around Patroclus' body.
(18) Achilles is mad with grief when he hears of Patroclus' death and vows to take vengeance on Hector; his mother Thetis grieves, too, knowing that Achilles is fated to die young if he kills Hector. Achilles is urged to help retrieve Patroclus' body but has no armour. Bathed in a brilliant radiance by Athena, Achilles stands next to the Greek wall and roars in rage. The Trojans are dismayed by his appearance, and the Greeks manage to bear Patroclus' body away. Polydamas urges Hector again to withdraw into the city; again Hector refuses, and the Trojans camp on the plain at nightfall. Patroclus is mourned. Meanwhile, at Thetis' request, Hephaestus fashions a new set of armor for Achilles, including a magnificently wrought shield.
(19) In the morning, Agamemnon gives Achilles all the promised gifts, including Briseis, but Achilles is indifferent to them. Achilles fasts while the Greeks take their meal, straps on his new armor, and takes up his great spear. His horse Xanthos prophesies to Achilles his death. Achilles drives his chariot into battle.
(20) Zeus lifts the ban on the gods' interference, and the gods freely help both sides. Achilles, burning with rage and grief, slays many.
(21) Driving the Trojans before him, Achilles cuts off half their number in the river Skamandros and proceeds to slaughter them, filling the river with the dead. The river, angry at the killing, confronts Achilles but is beaten back by Hephaestus' firestorm. The gods fight among themselves. The great gates of the city are opened to receive the fleeing Trojans, and Apollo leads Achilles away from the city by pretending to be a Trojan.
(22) When Apollo reveals himself to Achilles, the Trojans have retreated into the city, all except for Hector, who, having twice ignored the counsels of Polydamas, feels the shame of the rout and resolves to face Achilles, despite the pleas of his parents, Priam and Hecuba. When Achilles approaches, Hector's will fails him, and he is chased around the city by Achilles. Finally, Athena tricks him into stopping, and he turns to face his opponent. After a brief duel, Achilles stabs Hector through the neck. Before dying, Hector reminds Achilles that he, too, is fated to die in the war. Achilles takes Hector's body and dishonours it by dragging it behind his chariot.
(23) The ghost of Patroclus comes to Achilles in a dream, urging him to carry out his burial rites and to arrange for their bones to be entombed together. The Greeks hold a day of funeral games, and Achilles gives out the prizes.
(24) Dismayed by Achilles' continued abuse of Hector's body, Zeus decides that it must be returned to Priam. Led by Hermes, Priam takes a wagon out of Troy, across the plains, and into the Greek camp unnoticed. He clasps Achilles by the knees and begs for his son's body. Achilles is moved to tears, and the two lament their losses in the war. After a meal, Priam carries Hector's body back into Troy. Hector is buried, and the city mourns.