The Iliad is an epic poem that tells part of the story of the Trojan War. The poem was composed by Homer between about 750 and 650 BC. Epic in the ancient Greek world was a long, narrative form of poetry with a particular metre (hexameters) and subject matter drawn from heroic mythology. It was originally part of an oral (recited) tradition.
The title derives from Ilios, one of the names of Troy, and the Trojan War was a particularly important episode in the legendary past of Greece. Homer's audience would have known the whole story, from the Judgement of Paris to the ruse of the Wooden Horse and the fall of the city. This wider picture is referred to in the Iliad, but only a small part of the story is told. The action focuses on Achilles' withdrawal from the fight, and the death of his friend Patroklos who has taken his place. Achilles, in vengeful fury, rejoins the battle: he kills the Trojan hero Hector, and the Iliad ends with Hector's funeral games.
The gods play their part in the drama, but essentially the story concerns the heroic deeds of men. The Trojan War was widely accepted as a historical event in antiquity, though no independent authority confirms this. Archaeology provides a plausible background for the war, but cannot prove specifically that the event took place.