Aeneas was born on Mount Ida, the forested mountain that rises above the plain of Troy, from a union arranged by Zeus himself as a lesson in humility. The king of the gods had grown weary of Aphrodite, the goddess of love, meddling in the affairs of other immortals and making them fall in love with mortals. In retaliation, Zeus filled Aphrodite's own heart with longing for Anchises, a handsome Trojan prince who was tending his cattle on the slopes of Ida. The goddess came to him disguised as a mortal maiden, and when she revealed her true form the next morning, Anchises was struck with terror. She told him they would have a son named Aeneas, a name drawn from the Greek word for terrible grief, for the sorrow his mortality would bring her. She warned Anchises never to reveal the boy's divine parentage, but he did so anyway and was crippled by a thunderbolt from Zeus. The infant Aeneas was raised by mountain nymphs until the age of five, when he was brought to his father in Troy and accepted into the royal household as a prince of the blood.

When the Greeks laid siege to Troy, Aeneas fought with a fury that made him second only to Hector, the heir to the Trojan throne and the greatest warrior the city possessed. But Aeneas was not fully trusted by King Priam, the aged ruler of Troy and father of Hector and Paris, for an ancient prophecy had foretold that the descendants of Aeneas, not Priam's own line, would one day rule the Trojans. The gods protected Aeneas throughout the war. In one battle, the Greek hero Diomedes, a warrior of terrifying strength who had been granted temporary power by the goddess Athena, struck Aeneas with a massive stone and would have killed him had not Aphrodite swept down to shield her son, and then Apollo, the god of music, prophecy, and archery, carried him from the field to be healed. In another clash, Aeneas faced Achilles, the greatest Greek warrior of all, the son of the sea-goddess Thetis whose single weak spot was his heel. Poseidon, the god of the sea, intervened directly, enveloping Aeneas in a golden mist and whisking him away because the god knew that Aeneas was destined to survive and father a great people far to the west.

The end came for Troy through cunning rather than force. The Greeks left a giant wooden horse outside the walls and pretended to sail away. The priest Laocoon, a Trojan seer who served the god Poseidon, warned the Trojans not to trust the gift, but when sea serpents sent by the gods strangled him and his sons, the Trojans took the horse inside. That night, Greek soldiers hidden within opened the gates, and the city burned. As the flames rose, the ghost of Hector appeared to Aeneas in a dream, his body still bearing the wounds from his duel with Achilles, and commanded him to flee. Aeneas had wanted to fight to the death, but the vision convinced him that his duty lay in survival. He returned to his house, lifted his crippled father Anchises onto his shoulders, took his young son Ascanius by the hand, and led a band of survivors through the burning streets. His wife Creusa followed behind, but in the chaos she was lost. Aeneas searched for her desperately, and her ghost appeared to him to say that she was already dead and that he must go on without her, for a glorious kingdom awaited him in a western land.

The Trojans built a fleet and sailed first to Thrace, where Aeneas tried to found a settlement, but the spirit of the murdered Trojan prince Polydorus rose from the earth and warned him away. They stopped at Delos, where the oracle of Apollo told them to seek the land of their ancestors, which Anchises mistakenly identified as Crete. They landed on Crete and began to build a city, but a plague struck them, and the household gods of Troy appeared to Aeneas in a dream to correct the error: their true ancestral land was Italy. On the island of the Strophades, they were attacked by the Harpies, filthy winged creatures with women's faces who snatched their food and cursed them with prophecy of endless hunger. In Epirus, they found Helenus, a Trojan prophet who had married Andromache, the widow of Hector, and he foretold the trials ahead: the land of the Cyclopes, the kingdom of Carthage, and the coast of Italy itself.

The journey brought them to Sicily, where Anchises, already old and weakened, died peacefully and was buried with honour. From there, a storm raised by Juno, the Roman queen of the gods who hated the Trojans for the slight that Paris, the Trojan prince whose abduction of Helen, the most beautiful woman in Greece and wife of the Spartan king Menelaus, had started the war, had paid her long ago, drove their ships onto the shores of North Africa. There Aeneas found Carthage, a rising city ruled by Queen Dido, a widow of extraordinary beauty and intelligence who had fled from her brother's murder of her husband. Dido welcomed the Trojans and fell deeply in love with Aeneas, and for a time he forgot his destiny in the warmth of her court. But Mercury, the messenger of the gods, came to him with a stern command from Jupiter, the king of the Roman gods: Aeneas must leave Carthage and continue to Italy. He obeyed, though the departure drove Dido to despair. She built a funeral pyre, cursed the name of Aeneas, and fell upon his sword, her death sowing the seeds of the later hatred between Rome and Carthage that would erupt in three terrible wars.

Before reaching Italy, Aeneas sailed to Cumae near Naples, where the Sibyl, a prophetess who spoke the words of Apollo, led him down into the underworld through a cave at the edge of a dark lake. There he met the ghost of his father Anchises, who showed him a vision of Rome's future glory: the long line of his descendants, from the kings of Alba Longa to Romulus and Remus, and finally to Augustus Caesar, the first Roman emperor, under whose rule the world would know peace. Aeneas emerged from the underworld renewed in purpose, ready to accept the burden of empire.

When the Trojans landed at the mouth of the Tiber in Italy, they were received by King Latinus, the ruler of the Latins whose oracle had told him that his daughter Lavinia would marry a foreign prince and together they would found a mighty race. But Turnus, the prince of the Rutulians and Lavinia's previous suitor, refused to yield her to a Trojan exile, and war broke out. Aeneas forged an alliance with Evander, the Greek king of a settlement on the Palatine Hill, and with the Etruscans, a powerful people of central Italy who had risen against Turnus's tyranny. The fighting was savage. Pallas, the young son of Evander, was killed by Turnus, and Aeneas's fury knew no bounds. In the final duel, Aeneas wounded Turnus and would have spared him, but when he saw that Turnus was wearing the belt of the dead Pallas, he drove his sword through the Rutulian's heart. With Turnus dead, Aeneas married Lavinia and founded the city of Lavinium, named for her. Years later, he disappeared during a battle against the Rutulians or in a storm on the River Numicus. His body was never found, and the Latins worshipped him as a local god, Jupiter Indiges, the native Jupiter who had returned to the divine realm from which his mother had come.