The Shield of Achilles was born in fire and grief. When Patroclus, the son of Menoetius and the closest companion of Achilles, put on the hero's own armour and led the Myrmidons into battle to save the Greek ships from the Trojans, he was met by Hector, the eldest son of King Priam of Troy and the greatest warrior the city had ever produced. Hector killed Patroclus, stripped the armour from his body, and wore it himself, and Achilles was driven mad with grief and rage. He had refused to fight because Agamemnon, the king of Mycenae and commander of the Greek armies, had taken his war-prize Briseis, but the death of Patroclus changed everything. Achilles swore to kill Hector and every Trojan he could reach, but he had no armour. His mother Thetis, the sea nymph who had dipped him in the River Styx as an infant to make his body invulnerable, heard his cries from the depths of the sea and rose to Mount Olympus to beg a favour of Hephaestus.

Hephaestus was the son of Hera, the queen of Olympus, and the greatest craftsman the cosmos had ever known. He had built the palaces of the gods, forged the thunderbolt of Zeus, and crafted armour for heroes before, but never had he been asked to work with such urgency. Thetis found him at his forge, sweating over the bellows, his lame leg supporting him against the anvil, and she reminded him of a kindness he owed her, for she had once sheltered him when Hera cast him from Olympus in anger. Hephaestus agreed. He set aside his other work, stoked the fires to white heat, and began to hammer.

What he made was not merely a shield. It was a vision of the world. The shield was vast, five layers thick, of bronze and tin and silver and gold, a disc so wide and heavy that no mortal smith could have lifted it. Around the rim Hephaestus hammered the River Oceanus, the world-encircling stream that the Greeks believed flowed around the edge of the flat earth. Inside that ring he placed the earth, the sea, the sky, the sun and moon and all the stars in their constellations. Then he turned to the works of men. In one scene he hammered a city at peace, where weddings were being celebrated in the streets and a dispute was being argued before a council of elders, the very image of justice and order. In the next scene he hammered a city at war, where armies clashed at the gates and the goddess Athena, the goddess of wisdom and war, led one side while Ares, the Olympian god of war, led the other, and the personifications of Strife and Terror stalked the battlefield.

Below the cities he placed the seasons of human labour. He hammered a field being ploughed by oxen, the soil turning dark behind the blade. He hammered a harvest, where reapers cut the golden grain and binders gathered it into sheaves while a king stood watching beneath an oak tree, his heralds preparing a feast of roast meat. He hammered a vineyard, where youths trod the grapes in a wine-press while a boy played the lyre and sang, and girls danced in a ring. He hammered a cattle raid, where lions attacked a herd while the herdsmen and their dogs tried to drive them off. And in the centre, the heart of the shield, he hammered a dance floor where young men and maidens moved in circles, their hands linked, the girls in linen dresses and the boys in tunics rubbed with oil, while a crowd watched and two tumblers sprang and flipped through the midst of the dancers. The whole of human life was there, from war to wedding, from ploughing to dancing, from birth to death, all contained within the bronze disc that a single man would carry on his arm.

When the shield was finished, Hephaestus added a breastplate of shining tin, a helmet with a golden crest that nodded like a star, and greaves of flexible tin. Thetis carried them down from Olympus through the sea and brought them to her son in the Greek camp. Achilles took up the armour and his eyes blazed with a terrible light, for the shield seemed to burn with the fire of the forge and the fire of his own rage. He called the Greek army to assembly, ended his quarrel with Agamemnon, and prepared to enter battle.

The shield's first test came when Achilles charged the Trojan lines. He was like a fire that nothing could stop, and the Trojans broke before him. He drove them back to the River Scamander, the river that flowed past Troy, and so many men fell into its waters that the river itself rose in anger and tried to drown him. But Achilles fought free and pressed on, the shield gleaming before him like a second sun. At last he found Hector before the walls of Troy, and the two greatest warriors of the war faced each other. Hector wore the armour he had stripped from Patroclus, the armour that had once belonged to Achilles, and for a moment the hero who had made the shield faced the hero who wore his old one. They circled, they threw spears, they closed with swords, and Achilles, guided by Athena, struck Hector through the throat. As Hector died, he begged for his body to be returned to his father Priam for proper burial, but Achilles, still burning with grief, refused. He dragged Hector's body behind his chariot around the walls of Troy, the shield of Hephaestus gleaming in the dust, and for twelve days he defiled the corpse while the old king wept inside the city.

The shield appears one last time in the story of Achilles' death. After Hector was dead, the Trojan prince Paris, the same man whose abduction of Helen had started the war, shot Achilles in the heel with an arrow guided by Apollo, the god of archery. The heel was the one spot where Thetis had held her son when she dipped him in the Styx, the only part of his body that was not invulnerable. Achilles fell, and the Greeks mourned him for seventeen days. When his body was burned on the pyre, his ashes were mixed with those of Patroclus and placed in a golden urn, but his armour, the divine gift of Hephaestus, remained. The Greek heroes Ajax, the prince of Salamis and the strongest man in the army after Achilles, and Odysseus, the cunning king of Ithaca whose ten-year voyage home would become the subject of Homer's Odyssey, both claimed the armour. They argued before the army, and Odysseus won by eloquence. Ajax, driven mad with shame, fell upon his own sword. The shield that had contained the whole world had destroyed the man who could not bear to lose it.