The cultural atmosphere of Belfast in the early 1960s is hard to recapture. Given what happened from 1968-9, when communal violence broke out, the British army moved in, and three decades of murderous conflict commenced, images of a calm before a storm are inescapable. But it did not always seem like that at the time.

Patterns of sectarian discrimination ran deep and were carefully negotiated; the representatives of state power were blatantly and often oppressively Protestant; the underside of violence sometimes broke through (as captured chillingly in a 1964 short story by the poet John Montague, The Cry).

Much recent analysis, however, has represented life in Northern Ireland (particularly middle-class life) in the early 1960s in terms of the thawing of antagonisms and the hesitant beginnings of a more pluralist culture.

Heaney’s own recollections are not inconsistent with this. But even if the advent of apocalypse after 1968 is seen as an avoidable lurch into violence rather than the inevitable bursting of a boil, it fed on ancient antipathies as well as recent injustices.

In some senses, the Queen’s University of the 1960s was at an angle to this universe. It certainly represented the unionist governing class, and it was seen by some as a kind of colonial outpost. A large proportion of its teaching staff were British, and many returned to “the mainland” when teaching terms were over. But this detachment, while accompanied by a fair amount of condescension sharply noted by the locals, helped insulate the Queen’s common-room life from more atavistic attitudes, as Heaney himself recalled.

At the same time, the underlying realities of his native province were grist to his mill. A poem called Lint Water was published in the Times Literary Supplement on August 5th, 1965, though not reprinted in his first collection, Death of a Naturalist, a year later (nor anywhere else). The quintessential Ulster industry of linen-making provided a metaphor for the poisoning of running water; Northern Irish readers would be well aware that historically, linen making was notably sectarian in its work patterns. “Putrid currents floated trout to the loch, / Their bellies white as linen tablecloths”.

The idea of a poisoned terrain (also used by Montague for his landmark collection, Poisoned Lands, in 1961) was both irresistible and significant. So is the powerful authorial stamp carried by the poem, which signals the way that Heaney would choose to approach and unpick the tensions of his native province.

His own family’s relations with neighbouring Protestant farmers were amicable and equable; there was a sense of difference rather than superiority or exploitation. (With Unionist grandees such as the Chichester-Clark family in the neighbouring Big House, Moyola Park, the gap would be much wider and more definitive, both socially and politically.) Heaney’s father, according to his son, possessed the cattle-dealer’s wide franchise of moving easily through different circles of rural life, while his mother retained a stronger sense of historic grievance.

The poems which Heaney was planting out in Irish newspapers and magazines in the early 1960s made him a name to watch; a cyclostyled sheet of a poetry reading around 1963-4, including several of his first published poems, records him as “Seamus Heine”, which may or may not be a joke. But he was one of an extraordinarily talented group of Belfast-based writers who assembled to discuss their work under the aegis of the academic and poet Philip Hobsbaum, from 1963. They included the playwright Stewart Parker, the novelist and short-story writer Bernard McLaverty, the critic Edna Longley, and the poets Michael Longley, Joan Newmann, and James Simmons.

Later commentators have queried the extent to which these writers formed a selfdefining “group”, and so have some of the writers themselves. But studies by Heather Clark and others suggest an undeniable esprit de corps, if not of joint endeavour, at the time. There was certainly a remarkable “coincidence of talent”, in Michael Longley’s phrase, and a practice - as Heaney put it - of “doing committee work” on each other’s poems.

This much-mythologised “group” was undeniably important to Heaney’s poetic development, but so were other poets then based or partly based in Northern Ireland such as John Hewitt, Derek Mahon and John Montague, the painters Terry Flanagan and Colin Middleton, and the musician David Hammond. Longley, Mahon, and Heaney would become the great triumvirate of Northern poets, with Montague their bridge to an older generation; members of a formidably accomplished younger generation would follow in their wake, such as Tom Paulin, Paul Muldoon and Ciaran Carson.

Between their elders, an inevitable rivalry was maintained, but there was also a certain difference of influence and ethos. Queen’s kept Heaney and his school friend Seamus Deane within the Northern habitus (though it was praise from the South African poet Laurence Lerner, then on the faculty, that helped spur Heaney towards the literary life). In a later barbed reminiscence, Deane recalled that when he and Heaney discussed their own writing, they adhered to given roles: Deane excitingly experimental, Heaney imitative, modest, and careful. This memory reflected divergences on several levels over the intervening decades. But more generously, Deane also recalled his realisation that Heaney’s precision was the mark of someone who was writing poems rather than (as in his own case) attempting “poetry”.

Other kinds of difference can be charted too. Both of the Longleys and Mahon were products of Trinity College Dublin, a distinctively different culture; Heaney later recalled their superior sophistication at this stage. In particular, Mahon’s authoritative irony carried the impress of that peculiar institution. The concentrated slow burn of Longley’s poems, engineered for the long distance, also differed from Heaney’s occasional dramatic effects. For Longley and especially Mahon, Louis MacNeice was a vitally important precursor; Edna Longley would become the most incisive authority on this other “Northern poet”, who left Ireland far behind him but whose Irishness haunts his autobiographical magnum opus Autumn Journal and much else.

MacNeice, son of a Church of Ireland bishop, was also enduringly conscious of his Protestant inheritance of difference: “banned forever from the candles of the Irish poor”. It is questionable how far this muffled his influence over Heaney, who was at this stage still semi-immersed in a traditional Catholic background (making a pilgrimage to Lourdes when he was 19, abstaining from alcohol under the influence of a devout Pioneer aunt until the age of 20).

More immediately, the question of Longley’s and Mahon’s Protestant backgrounds cannot be dismissed as irrelevant, either to their own poetic consciousness or to their relation to Heaney’s.

Heaney admitted that MacNeice did not - at this stage - “speak” to him; he would later stress that his immersion in Catholic theology and practice at St Columb’s, “living the liturgical year in a very intense way”, instilled an atmosphere which attuned him to Hopkins - a Catholic priest - as his “main man”. “What you encounter in Hopkins’s journals - the claustrophobia and scrupulosity and ordering of the mind, the cold-water shaves and the single iron beds, the soutanes and the self-denial - that was the world I was living in when I first read his poems.”

A Catholicism of the imagination would remain. But the austere privations of St Columb’s were a world away from the atmosphere of literary bohemian Belfast a decade later: the poetry workshops, the blossoming of short-lived journals, convivial parties around Queen’s, the acting world based on the Lyric Theatre where Heaney first saw Yeats’s plays. (Heaney himself had a brief fling at acting in 1959-60, later rather lost from the record, but much praised in the local press: “Never has there been a more true characterisation [of the nationalist hero Robert Emmet] than that which is now being given by student Seamus Heaney. His movements and gestures are perfect while his diction leaves nothing to be desired”.)

He also at this time met and became close friends with David Hammond, the charismatic folk musician, filmmaker, and educationalist, whom Heaney described as “a natural force masquerading as a human being”. Hammond, as Heaney saw it, was immune to Belfast’s constricting ideologies and “knew the codes of a divided society so well that he knew exactly how to break them, tactfully yet deliberately”.

In other ways too, the mid-1960s set out future patterns of Heaney’s life. In 1965, he married the dazzling Marie Devlin; after pursuing her for some time, he realised (he told Deane) that she was “not so much a quarry, more a way of life”. This was prophetic. From a large and talented family which also produced writers and musicians, she was beautiful, clever, a teacher and editor, a close reader of poetry, and as strongminded as himself. Their marriage formed the rock-like foundation of his private life. Three children followed: Christopher, Michael and Catherine.

The Heaney household was a centre of gregarious social life, especially when they moved into 16 Ashley Avenue, where meetings of the poetry group shifted after Hobsbaum’s departure from Belfast in 1966. The house was a hub of activity and conviviality. Hammond would recall it elegiacally long afterwards, when the Ashley Avenue house was scheduled for demolition, in spite of efforts to preserve it in view of its now famous previous owner.

Walking past the shuttered and vandalised house, Hammond recalled parties, music sessions, the constant to-and-fro of neighbours in the late 1960s, local friends such as the Longleys and the painters Colin Middleton and Terry Flanagan, visiting Americans, the poet Ted Hughes and the playwright Trevor Griffiths from England, all contributing to an unforgettable atmosphere; the house throbbed with energy, he recalled, and the door was always open.

By a strange poetic transference, later still, Heaney would use that same image - a house with the door standing open - for The Door Was Open and the House Was Dark, a plangent elegy in memory of Hammond, who died in 2008.

Heaney’s explosive sense of humour, energetic joie de vivre, and legendary dispensation of hospitality created a focus of warmth and life, and a resonance that remained long after the family left Belfast; but he was simultaneously putting in hard work at poetry, often late at night. In a student magazine of 1961, he had described himself as an “ex-poet”, but he was now committed to his craft. Though the early spell of Hopkins wore off, it remained true that up to this time, as he put it himself, “the linguistic experiences that threw my switches were English”. Fittingly, his early poems, and his first collections, repeatedly if implicitly invoked Wordsworthian “spots of time”, though Kavanagh’s influence was increasingly clear as well.

His breakthrough to a wider audience than Belfast came early on. In late 1964, the literary editor of the New Statesman, Karl Miller, published three Heaney poems, which attracted the attention of Faber and Faber, the premier British publishing house for poetry. A pamphlet of 11 poems was published in 1965 by the Queen’s University Festival; Dolmen Press in the Republic was offered a potential collection by Heaney, but given the generally shambolic organisation there, its fate was uncertain. A letter from Liam Miller in the Heaney archives suggests that with Faber in prospect, Heaney reclaimed the poems and constructed a slightly different selection. This was swiftly accepted by Charles Monteith, whom Heaney had met when he visited the publishers’ office on his honeymoon trip to London. Monteith was a fellow Northerner, from a conspicuously different background but with a sharp eye for talent and a rapid comprehension of the heft and originality implicit in the poems that Heaney sent him. Death of a Naturalist was published on May 19th, 1966, costing 18 shillings. It would prove as vital a point in Faber’s history as in Heaney’s.