"The Aeneid centers on an eponymous hero, Aeneas, who escapes from the clutches of the Greeks during the fall of Troy and travels all over the Mediterranean before he arrives in Italy, gets re-married, and founds a city that will found a city that will found Rome. Bear in mind, the Rome in which Virgil writes the Aeneid conquered Greece and Carthage well before Virgil was born, and now faced newer enemies on its frontiers. Sounds a bit like Halo, if you relax your ears."
In "Bungie's Epic Achievement," Roger Travis compares Halo to Virgil's ancient masterpiece, The Aeneid, with surprising results.