From a historical point of view, it is said that it was probably a trade war, as Troy was an important trading centre in its time. According to another version, it was an escalation of hostilities between Locra and Priam when Priam's sister was kidnapped.

According to Homer, the reason for the Trojan War was the abduction of the beautiful Helen, daughter of the Spartan king Tyndareus, who was seized by Paris. Helena chose Menelaus, the richest of the Achaeans, as her future husband and thus the future king of Sparta. Paris was the cursed son of King Priam and his wife, Hekabe. He was to be put to death immediately after his birth because the oracle said he would be the ruin not only of his family but of all Troy. But his parents were unable to kill him, and he was taken from the city, where he was raised by Agelaos, the keeper of the flocks.

Helen and Paris would never have met if it hadn't been for a dispute between the goddesses Hera, Aphrodite and Athena over which of them was the most beautiful. This conflict was sparked by the goddess of strife, Eris, when she presented the goddesses with a golden apple inscribed "the fairest". It was Paris who was to decide their dispute. Each of the goddesses offered him great gifts, but only Aphrodite offered him the most precious gift - love. She promised him the heart of the beautiful Helen. Paris therefore chose Aphrodite as the most beautiful, and soon afterwards he met Helen, who fell so in love with him that she fled with him to Troy. This act greatly angered her husband Menelaus, and he and his brother Agamemnon decided to march an army against Troy and reclaim Helen.

As many as 1,144 ships from all parts of Greece were to join the war, including soldiers from Athens, Sparta, Mycenae, Salamis, Crete and others. Most of the leaders of these armies were former suitors of Helen, who promised each other that whichever one Helen chose, the others would swear allegiance to him. And so the heroes Odysseus, Achilles, the Great Aias of Salamis, Patroclus, Diomedes, and others joined in the fighting.

Most of the Greek heroes distinguished themselves in the battles of Troy and gained even greater glory. Achilles (son of King Peleus and the sea goddess Thetis) was most famous there. His fate was that he would either become famous but die, or else live long but not be famous. His mother did not want to see him dead, so she decided to hide him in a girl's dress in the palace of the Skyrian king Lycomedes. But Odysseus saw through the disguise, and Achilles promised to lead his tribe of Myrmidons to Troy.

When the Greek ships arrived at Troy, the warriors set up a camp from which they plundered the entire area around Troy, but they were unable to conquer Troy itself. The oracle determined that Troy would not fall until Priam's son Troilus was twenty years old. Moreover, the forces of the two rival armies were fairly evenly matched, as the Lycians, Mycenaeans, Kikons, Dardanians, Maiones, Phrygians, Cæsars, Pelasgians and Halisgonians joined the side of Troy.

It was not until the tenth year that the Greeks focused on the conquest of Troy itself. This year, however, was marked by the kidnapping of the daughter of Apollo's priest Chryseus by the Greek commander, the Mycenaean king Agamemnon. Apollo, out of anger, sent a plague on his camp. The plague constricted the soldiers for ten days before Agamemnon decided to return his daughter to her father. However, he chose Achilles' mistress Briseis as a replacement, which caused a feud between him and Achilles. Achilles then refused to fight for Agamemnon, and so did his Myrmidons. Agamemnon then declared that he had no need of them.

The war itself was intertwined with the intrigues of the gods. On the side of the Greeks were, for example, Poseidon, Hera, Pallas Athena and Achilles' mother goddess Thetis. On the side of Troy stood Zeus, Ares and Apollo.

Zeus summoned Agamemnon in a dream, urging him to attack. The Greeks took to the run, but Paris decided to settle the dispute with a duel to the death between himself and Menelaus. Thus a truce was made and their duel ensued. But Paris was losing, and he was saved by Aphrodite. The warrior Pandaros disobeyed the peace and wounded Menelaus with an arrow. A great battle ensued, which in the end had no victor, as both sides agreed to a truce until the dead of both sides were buried.

In the days that followed, successes in the fighting spilled over from one side to the other. One day the Trojans even pushed the Greeks up to their ships, but Patroclus appeared. Patroclus was a loyal comrade of Achilles and asked him to lend him his armor so he could go fight. But Hector, the son of King Priam, recognized that the weaker Patroclus was hiding in Achilles' armor and challenged him to a duel. In the duel, he killed Patroclus. Achilles was devastated by this loss and decided to take revenge on the Trojans. He reentered the battlefield and it was through him that the Trojans were driven back into their walls. He had the upper hand in his duel with Hector and after killing him, he further dishonored his body (dragging his body around the Trojan walls). Subsequently, however, Achilles was struck in the heel, his only vulnerable spot, by an arrow from Paridus, guided by Apollo himself. Achilles died from this wound.

The conquest of Troy itself is not described by Homer, but is narrated by Virgil in Aeneis. The goddess Athena gave Phrylides the idea of building a hollow wooden horse out of ship hulls, in which 20 to 30 soldiers would hide. The rest of the army will sail over the horizon. When the Trojans found the empty camp and this horse, they considered it a peace offering and took it back to their city. There they celebrated mightily. When night came, the Greeks came out of the horse, who killed the guards, opened the city gates, and signaled their ships to land an army to destroy Troy. It was eventually burned to the ground.

Meneláos, however, did not for a moment consider punishing Helen, and was convinced that Paris alone was behind everything. Helena then willingly returned to Sparta.