''Forsan et haec olim meminisse juvabit,'' Aeneas tells his exhausted, shipwrecked followers in ''The Aeneid,'' Book 1. ''Maybe someday you will rejoice to recall even this.''

Legions of high school Latin teachers used to joke that the line also applied to their miserable students, just then embarking on Virgil's epic, with 12,000 lines of dense, highly inflected Latin verse ahead of them: battles, catalogs, run-on similes, thickets of arcane vocabulary, and arduous slogs between the good parts, like Dido and Aeneas having sex in the cave (Dido ''ablaze with love, drawing the frenzy deep into her bones'') and that excellent passage in Book 9 when Turnus splits Pandarus in two, right down the middle, leaving his head to roll loose on the ground.

Veterans of those arduous classroom campaigns, as well as succeeding generations of students for whom Virgil was never on the reading list, can now turn gratefully to Robert Fagles's new English translation of ''The Aeneid'' (Viking), in which that ancient war horse emerges as a work of surpassing beauty, feeling and even relevance, everything that teachers used to say it was.

''I usually try not to ride the horse of relevance very hard,'' Mr. Fagles said recently at his home near Princeton University, from which he recently retired, after teaching comparative literature for more than 40 years. ''My feeling is that if something is timeless, then it will also be timely.'' But he went on to say that ''The Aeneid'' did speak to the contemporary situation. It's a poem about empire, he explained, and was commissioned by the emperor Augustus to celebrate the spread of Roman civilization.

''To begin with, it's a cautionary tale,'' Mr. Fagles said. ''About the terrible ills that attend empire -- its war-making capacity, the loss of blood and treasure both. But it's all done in the name of the rule of law, which you'd have a hard time ascribing to what we're doing in the Middle East today.

''It's also a tale of exhortation. It says that if you depart from the civilized, then you become a murderer. The price of empire is very steep, but Virgil shows how it is to be earned, if it's to be earned at all. The poem can be read as an exhortation for us to behave ourselves, which is a horse of relevance that ought to be ridden.''

The publication of this ''Aeneid'' is the end of an epic journey of sorts for Mr. Fagles, now 73, who before turning to Virgil translated first ''The Iliad'' and then ''The Odyssey.'' He is one of very few translators to make it through all three of the great classical epics, and to his surprise, he has become famous in the process. Both his ''Iliad,'' which came out in 1990, and his ''Odyssey,'' appearing in 1996, were unexpected best sellers, and his publisher has similar expectations for ''The Aeneid,'' in bookstores on Thursday.

Some of the success of the Homer translations is doubtless attributable to the glamorous, high-powered audio versions, released almost simultaneously with the print ones. Derek Jacobi recorded Mr. Fagles's ''Iliad,'' with great rhetorical force, and Ian McKellen his ''Odyssey,'' with particular feeling for the more intimate moments.

This is the way Homer meant us to appreciate his poems, Mr. Fagles pointed out: by hearing them. Noting that another great British actor, Simon Callow, had been recruited for the new ''Aeneid,'' he said that, though written down, that poem too is a kind of performance.

But another reason for the success of the Fagles translations is that there turned out to be a far greater audience for them than either the author or the publisher had anticipated. ''I was very surprised,'' Mr. Fagles said, ''because I'm an academic, and a lot of hand wringing goes on in the academy about the illiteracy of the public. The great joy of this work was to discover that there is in fact a great number of very intelligent, hardworking readers out there.''

Mr. Fagles himself never slogged through ''The Aeneid'' as a high school student. He didn't begin to learn Latin and Greek until he was a junior in college, and he taught himself. Even then, he recalled, he had ''Homer on the brain.''

An only child who was 14 when his father died, he was particularly struck when he read a version of Andromache's lament in ''The Iliad,'' when she mourns not just for her dead husband, Hector, but for their now fatherless infant son.

''Every now and then you pick up a book, whether it's Homer or Dante or whatever,'' he said, ''and you read something and think, 'My God, that's such a perfect image of me.' When I read that passage, it wasn't just that I could identify with the situation, but that the text took that situation and made it universal.''

Mr. Fagles went on to get a doctorate in English at Yale, where he continued to work -- ''backstairs,'' as he puts it -- on his classical languages. He never had a grand plan to take on the great epics, but he nevertheless began to set himself little tasks of Greek translation: first Pindar and then some of the tragedies before attempting some chunks of Homer.