Paris was born to Priam and Hecuba, the king and queen of Troy, a wealthy and powerful city on the northwestern coast of modern Turkey that controlled the trade routes between Europe and Asia. Before his birth, Hecuba dreamed that she gave birth to a burning torch that set the city ablaze, and the prophets of Troy warned that the child would be the ruin of the kingdom. Priam, desperate to save his city, ordered the infant to be exposed on Mount Ida, the mountain that rose above the Trojan plain, where the wild beasts and the elements would kill him. But a shepherd named Agelaus found the baby, still alive and suckling at the teat of a bear that had wandered by, and took him home to raise as his own. Paris grew up among the flocks, handsome and strong, with a gift for the bow and a pride that exceeded his station. He herded sheep on the slopes of Ida, and the other shepherds called him Alexandros, the defender, for he protected their flocks from wolves and brigands with a skill that seemed more than mortal.

The event that changed his fate and the fate of the world began at the wedding of Peleus, the mortal king, and Thetis, the sea-nymph, a union arranged by the gods because of a prophecy that their son would be greater than his father. All the gods were invited except Eris, the goddess of discord, whose presence promised strife. In revenge, Eris tossed a golden apple into the midst of the wedding feast, inscribed with the words "For the Fairest." Hera, Athena, and Aphrodite each claimed it, and Zeus, unwilling to judge between his wife, his daughter, and the goddess of love, commanded that the decision be made by the most beautiful mortal man alive. The three goddesses descended to Mount Ida and appeared before Paris as he tended his flocks. Hera offered him power and dominion over all of Asia. Athena offered him wisdom and victory in every battle. Aphrodite, knowing what would sway a young shepherd, offered him the love of Helen, the most beautiful woman in the world, who was then the wife of Menelaus, king of Sparta, a city in the southern Peloponnese of Greece. Paris awarded the apple to Aphrodite, and the two rejected goddesses swore vengeance on him and on all of Troy.

Paris sailed to Sparta as a guest of Menelaus, welcomed into the palace with the sacred laws of hospitality that the Greeks called xenia, which bound host and guest in mutual respect and protection. But while Menelaus was away on a mission to Crete, the large island south of the Greek mainland where the ancient Minoan civilization had once flourished, Paris broke that sacred bond. With Aphrodite's help, he persuaded Helen to flee with him, and they sailed back to Troy with the treasures of Sparta in their hold. When Menelaus returned and found his wife gone, he called upon the oath that all the princes of Greece had sworn when they competed for Helen's hand, an oath brokered by Odysseus, the cunning hero of Ithaca, that they would defend her chosen husband against any who took her away. The Greeks assembled a fleet of a thousand ships and sailed for Troy, and the war that would last ten years and end in the burning of the city began. Paris had not stolen a woman; he had stolen the peace of the world.

During the war, Paris proved himself a skilled archer but a poor warrior in close combat. He preferred to shoot from the walls of Troy rather than face the Greek champions in the field. He fought Menelaus in single combat in the third year of the war, a duel arranged to settle the conflict without further bloodshed. Menelaus, enraged and betrayed, battered Paris with spear and sword, tearing his helmet and driving him backward across the plain. Paris would have died, but Aphrodite, bound by her promise, wrapped him in a mist and carried him back to the safety of Troy, leaving Menelaus raging on the battlefield. This act of divine cowardice enraged the Trojans, who saw their prince saved by a goddess while their own sons died in the dust. Hector, Paris's elder brother and the greatest Trojan hero, a warrior of such nobility that even the Greeks honored him, rebuked Paris bitterly, calling him the ruin of Troy and begging him to face his fate like a man. Paris wept and promised to fight, but his courage failed him again and again.

Yet Paris had one great deed that shaped the war's end. Guided by Apollo, the god of music and prophecy, who had favored the Trojans from the beginning, Paris shot an arrow at Achilles, the greatest Greek warrior, whose rage and grief had defined the course of the war. Achilles was invulnerable everywhere except his heel, where his mother Thetis had held him when she dipped him in the waters of the River Styx, the boundary between the world of the living and the dead. Paris's arrow, guided by Apollo's divine aim, struck that one weak spot, and Achilles fell dead, the greatest hero of Greece slain by the coward whose abduction had started the war. But Paris did not live to see the fall of Troy. Philoctetes, the Greek archer who had been abandoned on the island of Lemnos for ten years because of a wound that would not heal, was fetched by Odysseus at the prophecy of the dying Trojan seer Helenus. Philoctetes carried the bow of Heracles, the hero forced to complete twelve impossible labors, and with it he shot Paris. The wound festered, and Paris, dying, sought out the nymph Oenone, a mountain spirit he had loved in his youth before Helen, but she refused to heal him, and he died on Mount Ida, where he had been born and abandoned, buried by the shepherds who had raised him.