What happens in Book XX of The Iliad?
With Achilles back on the battlefield, eager for revenge against the Trojans, Zeus calls the gods to Olympus and grants them the freedom to intervene in the fighting below — a sharp change from his earlier restrictions. The divine assembly divides along familiar lines: Hera, Athena, Poseidon, Hermes, and Hephaestus support the Achaeans, while Ares, Apollo, Artemis, Leto, Xanthus, and Aphrodite back the Trojans. As the two divine factions clash, the ground shakes, and even Hades feels the tremors in the underworld. Apollo, taking on the guise of the Trojan Lycaon, encourages Aeneas to face Achilles head-on. Aeneas agrees, and the two warriors exchange grand boasts before Achilles thrusts his spear through Aeneas's shield. Poseidon, not willing to let Aeneas meet his end before his time, whisks him away from the battlefield in a cloud. Achilles then carves a path through the Trojan forces, killing Iphition, Demoleon, Hippodamas, and Polydorus — Priam's youngest and most cherished son. When Hector finally charges to avenge Polydorus, Apollo diverts Achilles's spear and takes Hector away, leaving Achilles to unleash his fury on lesser Trojans, the book ending with the image of his relentless, almost superhuman advance.
Analysis
Book XX acts as a crucial turning point: Homer has kept Achilles out of the battle for nineteen books, and now, instead of just having him return, he reshapes the entire universe to accommodate that return. The release of the gods isn't just for show — it's Homer’s way of indicating that the usual rules of warfare no longer apply. When the earth shakes and Hades fears his roof might collapse, this exaggeration conveys an important tone: Achilles's return is a moment of mythic significance, not just a turning point in the plot.
The episode with Aeneas is crafted to serve as a contrast. Aeneas is courageous, blessed by the gods, and comes from an impressive lineage — his ancestry can be traced back to Zeus — yet Poseidon's intervention highlights what the poem subtly suggests elsewhere: it’s fate, not bravery, that determines survival. The rescue is remarkably detached; Poseidon saves Aeneas not out of love but because "it is not ordained" for him to die here. This unemotional divine logic sharply contrasts with Achilles's intense rage.
The death of Polydorus is the book's emotional turning point. Homer identifies him as Priam’s youngest and most beloved son, killed by a spear in the back while trying to show off his speed — youth, pride, and a father’s love obliterated in one image. This moment foreshadows the sorrow that will envelop Priam in Book XXIV and subtly portrays Achilles's fury as something that will ultimately cost everyone, including him, greatly. The book concludes not with victory but with a grim accumulation — bodies piling up, and Achilles remains unsatisfied — and that relentless nature becomes a source of dread.
Key quotes from Book XX
“So he spoke, and the son of Cronus roused the gods to war, and sent them forth to mingle in the battle.”
Zeus formally lifts his prohibition on divine intervention, triggering the theomachy that gives the book its name.
“Achilles swept through them like a god, and the black earth ran with blood.”
Homer's summary image of Achilles's rampage through the Trojan ranks in the book's closing movement, collapsing the human and divine into a single terrifying figure.
“It is not his fate to die here; the race of Dardanus must not perish without seed, for Zeus loved Dardanus beyond all sons that were born to him of mortal women.”
Poseidon explains to Hera why he intervenes to save Aeneas, foregrounding the poem's fatalistic architecture over individual heroic agency.