BOOK 1 - The Start of Achilles' Anger
The Iliad opens in the tenth year of the war, with no scene setting, in the Achaean camp. Chryses, the priest of Apollo, has come, bringing ransom with him, to plead with Agamemnon for the release of his daughter, Chryseis, whom Agamemnon has taken as his concubine. All the other Achaeans are in favour of her being returned to her father, but Agamemnon cruelly rejects his request and sends him on his way. Chastened, the old priest makes his way to the seashore, where he prays to Apollo that he may visit punishment upon them for their treatment of him. As a result, Apollo sends a plague that ravages their army for nine days.
On the tenth day, Achilles calls an assembly. A seer explains to Agamemnon the reason for Apollo's anger. Agamemnon turns angrily upon him and the confrontation leads to a quarrel with Achilles. Agamemnon states that, if he is to give up Chryseis, he wants another prize instead, and he threatens to take Achilles' own girl, Briseis. Achilles voices his contempt for Agamemnon and says that he will sail home, since he is never given the honour that he deserves for the services he performs. When Agamemnon confirms that he will take Briseis, Achilles is on the point of drawing his sword and attacking him, when he is restrained by Athena, who advises him to use words to discredit Agamemnon rather than the sword. Achilles confirms that he will fight no more and, after Nestor's failed attempt to broker a peace, the assembly disbands, with Achilles returning to his tents.
Despite the reluctance of the other Achaeans, the heralds sent to perform the task and the girl herself, Briseis is taken from Achilles, who promptly calls upon his mother, the sea-nymph Thetis, for comfort and advice. She tells him to withdraw from the fighting and promises that she will visit Zeus and ask him to honour Achilles, by granting success to the Trojans.
Having left Achilles, Thetis travels to Olympus, where she does what she promised. Zeus grants his assent to her plan, but Hera, noticing Thetis' visit, initiates a domestic wrangle with him. This results in Zeus threatening her with violence, a threat which sees the tension subside, and the gods fall to laughter at the figure of Hephaestus.
BOOK 2 - Catalogue of Ships
In order to effect what he has promised to Thetis, Zeus sends a false dream to Agamemnon, persuading him that he will be victorious and will capture Troy that very day, if he engages in a full-scale conflict. At the assembly that he calls subsequent to this dream, Agamemnon tests the loyalty of his men, by saying that Zeus has deceived him and that, as a result, they should all return home. Overjoyed at this news, the men make preparations for departure.
Prompted by Hera, Athena visits Odysseus and goads him to use soft words to persuade them to stay and fight on. Taking the sceptre of Agamemnon, Odysseus does this as far as the kings and leading men are concerned, but, in contrast, he berates the common men for their willingness to give up. As a result, the Achaean army stream back to the assembly, where the vulgar commoner Thersites taunts Agamemnon and advises the men to depart. Odysseus rebukes him and he and, after him, Nestor reminds the Achaeans of the favourable omens they received at Aulis, when they set off to come to Troy. Given this encouragement, the men prepare themselves for war.
The second half of the book comprises the Catalogue of Ships, which lists the Greek tribes present, their leaders, and the number of their ships. We are then treated to a shorter catalogue of the Trojan ships and those of their allies.
BOOK 3 - Paris' Duel
Before the armies can come together, Paris challenges the Achaeans to provide someone to fight him in a single duel. Menelaus accepts the challenge and it is agreed that the victor will gain possession of Helen and her goods. Furthermore a general truce and end to the hostilities will accompany the duel.
Helen moves the Scaean gates in order to watch the contest, and there, at Priam's behest, she points out the leading Achaeans.
The duel sees an effective victory for Menelaus, but Aphrodite rescues Paris and transports him to his bedroom. The goddess then summons Helen and forces her to sleep with him.
BOOK 4 - The Start of the Fighting
The book opens with a scene set on Olympus. In the courtyard of Zeus, the gods are enjoying themselves, drinking and watching the events occurring on earth. In order to provoke Hera, Zeus suggests bringing an end to the war. Unhappy at this, Hera and Athena insist that the war must not cease until Troy has been destroyed. Eventually, a compromise is reached, so that the issue might disturb the gods' peace no longer: the destruction of Troy is granted to Hera on the condition that Zeus, when he so desires, may destroy one of her favourite cities. Having agreed to this, Hera suggests three potential targets- Argos, Sparta and Mycenae. Athena is then dispatched in order to bring about the breaking of the truce by the Trojans.
Arriving at Troy, the goddess persuades Pandarus to shoot an arrow at Menelaus. As a result, the truce is broken and Agamemnon vows that Troy and its people will now be destroyed. As the Trojans advance, Agamemnon reviews his men and their commanders.
The two sides clash for the first time. Homer describes the fighting in detail, moving from the general picture of the multitude engaged, to a succession of individual, specific encounters. By the end of the book, it appears that the contest has been fairly even.