The Iliad takes place toward the end of the Trojan War, which, according to legend, began when Paris, a son of the king of Troy, abducted Helen, the wife of the Spartan king Menelaus. At the point Homer begins, Achilles, a Greek warrior, and Agamemnon, king of Mycenae and leader of the Greek army besieging Troy, quarrel over a captive woman, Briseis. Achilles withdraws in anger to his tent, while his mother, Thetis, a sea goddess, persuades Zeus to inflict losses on the Greeks and thus prove the value of Achilles to the Greek forces. After a long day of battle, the Greeks are reduced finally to approaching Achilles in an embassy. Though moved, Achilles holds firm.

The fighting continues until Achilles allows his beloved companion Patroclus to enter the war wearing Achilles’ own armor. Hector, the chief Trojan warrior, kills Patroclus and takes the armor, though the Greeks after an intense struggle win back the body. Thetis brings Achilles new armor, including a great, elaborately embossed shield. Achilles reenters the battle, slaughters Trojans relentlessly, kills Hector, and maltreats Hector’s corpse. Achilles then holds funeral games in Patroclus’ honor. The games, at which Achilles commands and Agamemnon remains in the background, also serve to restore him to his honored position in the warrior society. There is a profounder restoration of Achilles to his humanity when he gives back Hector’s body to Hector’s father, the aged king of Troy. The Trojans lament and bury Hector.

Though Homer knew the entire legend of the 10-year siege and refers both to early events and to Troy’s fall, he limits his material to a brief period of 50 days and creates a tightly unified structure; this is one of the chief reasons for the belief that the epic is the work of one man and not a compilation to which each generation added new modifications. The division of the material into 24 books, however, .is probably later. Though Homer is careful about the time scheme, the action follows its own inner time and its own carefully planned rhythms. Periods of 9 days are often covered in 30 lines, whereas long sections of many books deal with one day.