This translation of Aeneid VI is neither a “version” nor a crib: it is more like classics homework, the result of a lifelong desire to honour the memory of my Latin teacher at St Columb’s College, Father Michael McGlinchey. The set text for our A-level exam in 1957 was Aeneid IX but McGlinchey was forever sighing, “Och, boys, I wish it were Book VI.” Over the years, therefore, I gravitated towards that part of the poem and took special note of it after my father died, since the story it tells is that of Aeneas’s journey to meet the shade of his father Anchises in the land of the dead. But the impulse to go ahead with a rendering of the complete book arrived in 2007, as the result of a sequence of poems written to greet the birth of a first granddaughter.

The autobiographical sequence in 12 sections, published in Human Chain (2010), was entitled Route 110 and plotted incidents from my own life against certain well-known episodes in Book VI: thus a bus inspector’s direction of passengers to the bus for Route 110 – the one I often took from Belfast to my home in County Derry – paralleled the moment when Charon directs the shades on board his barge to cross the Styx; and a memory of the wake of a drowned neighbour whose body was not retrieved for three days shadowed the case of Aeneas’s drowned, unburied helmsman Palinurus. It was a matter, in other words, of a relatively simple “mythic method” being employed over the 12 sections. The focus this time, however, was not the meeting of the son with the father, but the vision of future Roman generations with which Book VI ends, specifically the moment on the bank of the River Lethe when we are shown the souls of those about to be reborn and return to life on Earth.

Facebook Twitter Pinterest Seamus Heaney. Photograph: Ian Georgeson/TSPL/Writer Pictures

Route 110 also ends with birth and the whole sequence is dedicated to “one / Whose long wait on the shaded bank has ended”. And so, elated and inspired by having completed the sequence in thanksgiving for that infant birth, and in memory of the man who first turned my ear and temperament to Virgil, I began work on a complete translation of Book VI. Yet as anyone familiar with this work knows, the beginning and middle of that book are alive with poetic and narrative energy, but not so the ending. By the time the story reaches its climax in Anchises’s vision of a glorious Roman race that will issue from Aeneas’s marriage with Lavinia, the translator is likely to have moved from inspiration to grim determination: the roll call of generals and imperial heroes, the allusions to variously famous or obscure historical victories and defeats, make this part of the poem something of a test for reader, and translator, alike. But for the sake of the little one whose “earthlight broke” in late 2006, and the one who sighed for his favourite Virgil in that 1950s classroom, it had to be gone through with.

McGlinchey created an inner literalist who still hunts for the main verb of a sentence and still, to the best of his ability, disentangles the subordinate clauses, although usually nowadays with the help of a crib from the Loeb Library or the old Penguin Classics. Yet nowadays, too, that sixth-form homunculus must contend with a different supervisor, a writer of verse who has things other than literal accuracy on his mind and in his ear: rhythm and metre and lineation, the voice and its pacing, the need for a diction decorous enough for Virgil but not so antique as to sound out of tune with a more contemporary idiom – all the fleeting, fitful anxieties that afflict the literary translator.

Extract from Aeneid Book VI

by Seamus Heaney

Thus from her innermost shrine the Sibyl of Cumae

Chanted menacing riddles and made the cave echo

With sayings where truths and enigmas were twined

Inextricably, while Apollo reined in her spasms

And curbed her, or sank the spurs in her ribs.

Then as her fit passed away and her raving went quiet,

Heroic Aeneas began: ‘No ordeal, O Sibyl, no new

Test can dismay me, for I have foreseen

And foresuffered all. But one thing I pray for

Especially: since here the gate opens, they say,

To the King of the Underworld’s realms, and here

In these shadowy marshes the Acheron floods

To the surface, vouchsafe me one look,

One face-to-face meeting with my dear father.

Point out the road, open the holy doors wide.

On these shoulders I bore him through flames

And a thousand enemy spears. In the thick of fighting

I saved him, and he was at my side then

On all my sea-crossings, battling tempests and tides,

A man in old age, worn out, not meant for duress.

He too it was who half-prayed and half-ordered me

To make this approach, to find and petition you.

Wherefore have pity, O most gracious one,

On a son and a father, for you have the power,

You whom Hecate named mistress of wooded Avernus.

If Orpheus could call back the shade of a wife

By trusting and tuning the strings of his Thracian lyre,

If Pollux could win back a brother by taking the road

Repeatedly in and out of the land of the dead,

If Theseus and Hercules too . . . But why speak of them?

I myself am of highest birth, a descendant of Jove.’

He was praying like that and holding on to the altar

When the Sibyl started to speak: ‘Blood relation

Of gods, Trojan, son of Anchises,

It is easy to descend into Avernus.

Death’s dark door stands open day and night.

But to retrace your steps and get back to upper air,

That is the task, that is the undertaking.

Only a few have prevailed, sons of gods

Whom Jupiter favoured, or heroes exalted to glory

By their own worth. At the centre it is all forest

And a ring of dark waters, the river Cocytus, furls

And flows round it. Still, if love so torments you,

If your need to be ferried twice across the Styx

And twice to explore that deep dark abyss

Is so overwhelming, if you will and must go

That far, understand what else you must do.

Hid in the thick of a tree is a golden bough,

Gold to the tips of its leaves and the base of its stem,

Sacred (tradition declares) to the queen of that place.

It is safe there, roofed in by forests, in the pathless

Shadowy valleys. No one is ever allowed

Down to earth’s hidden places unless he has first

Plucked this sprout of fledged gold from its tree

And handed it over to fair Proserpina

To whom it belongs, by decree, her own special gift.

And when it is plucked, a second one grows every time

In its place, golden again, emanating

That same sheen and shimmer. Therefore look up

And search deep, and as soon as you find it

Take hold of it boldly and duly. If fate has called you,

The bough will come away in your hand.

Otherwise, no strength you muster will break it,

Nor the hardest forged blade lop it off.

• Aeneid Book VI by Seamus Heaney is published by Faber on 7 March. To order a copy for £11.99 (RRP £14.99) go to bookshop.theguardian.com or call Guardian book service on 0330 333 6846.