How much of the Aeneid story is by Virgil?

Answer 1

Vergil wrote the poem, but there were certain pre-existing traditions that he drew from in crafting certain story elements. For example, there had already been a tradition in Italy that Aeneas came to Latium after the Trojan War. Vergil, of course, greatly expands upon this. More broadly, the work takes beats from its two biggest inspirations: Homer's Odyssey and Iliad. The first half of the Aeneid is known as "Odyssean," as it follows a long and torturous journey home. The second half the Aeneid is known as "Iliadic," since it recounts a war between two factions, the Trojans and the Latins. Vergil consciously mirrored his story to that of Homer's greatest epics but reframed it as a national epic—one that seeks to make a statement on the domination of the Roman people and Augustus' principate.