Troy has pretty much nothing to do with the Roman Empire (except that Vergil and a few other Romans liked to claim that the city was founded by fugitive Trojans, which even back then they knew was very unlikely.)
The Roman Empire has pretty much nothing to do with The Holy Roman Empire (barring the name).
So the mention of "Ileum" in the game has absolutely nothing to with the original PID plot. I'm not saying that that plot didn't find its way into Myth, just that this isn't one of the places it popped up. I don't know if anyone disagrees with me, but I thought I should say this because the subject veered away from Forrest's original question of "Ileum's" significance before any answers were suggested. My personal feeling on it is that Ileum was either the fortress of that Era's Leveler or the last bastion of the Light in that Era. Either way, the city was besieged for a time before the Leveler was killed and Bungie wanted its name to allude to the most famous besieged city in history.
--SiliconDream
