Ilium

Taking the events and characters of the Iliad as his jumping-off point, Dan Simmons has created an epic of time travel and savage warfare. Travellers from 40,000 years in the future return to Homer's Greece and rewrite history forever, their technology impacting on the population in a godlike fashion.

This is broad scope space opera rich in classical and literary allusion, from one of the key figures in 1990s world SF. Ilium marks a return to the genre for one of its greats.