There was a time during my early years on the staff of The Observer in London when the sports department’s office was next to that of the great literary editor Terence Kilmartin, whose distinctions would later include acclaim as a translator of Proust. Terry and our small crew found being neighbours agreeable and mutually interesting, so it was no surprise when he walked through our door on a May morning in 1966. But he made the moment more unusual by handing me two or three sheets of paper and saying: ‘Don’t you think, given that you’re working here, this might be seen as excessively favourable?’

What he had invited me to read was the fiction review by Irving Wardle that would appear in the following Sunday’s Observer. The piece was mainly devoted to glowing praise for my younger brother Willie’s debut novel, Remedy is None. It was a resounding, tribute-rich welcome for a talent Wardle identified as unmistakably powerful. Responding in kind to Kilmartin’s gentle ribbing, I said that, give or take an occasional susceptibility to understatement, his reviewer’s assessment seemed to be sound. My attempt at a cool reaction was probably unconvincing, considering how thrilled I was by the words I had been reading, just as I would be subsequently by reviews of Remedy is None in other publications, especially the unstinting and elegant compliments delivered by Frederic Raphael. Then and afterwards, when Willie’s work was exposed to judgement the emotional commitment of our family was often too intense to be explained simply as blood loyalty, though that was certainly strong enough. While my mother and my two dear and formidable older siblings, Betty and Neil, were still alive (we had lost our father to cancer in 1955), we all felt more than pride in his achievements.

I don’t think I exaggerate in suggesting that familial supportiveness was always reinforced by an awareness that Willie’s writing was giving a voice not only to our sense of ourselves but to an entire swathe of working-class experience, past and present. In me there was, at least early in his career as a novelist, a basic, almost objective anxiety that his books might be applauded yet underrated, that there would be slowness in recognising their real worth and importance. That worry had less to do with lack of faith in public perceptiveness than with the extent of my belief in how much he had to offer. Maybe it was feeble of me to be wanting reassurance that he was properly appreciated but I can’t deny the depth of satisfaction that came with the awarding of the 1975 Whitbread Prize for Fiction to Docherty. In making the presentation, the broadcaster and journalist Robert Robinson said that bracketing Docherty with the general run of novels dealing with working-class life would be as crass as describing Moby Dick as a rattling good yarn about the sea. When I mentioned the strength of that declaration admiringly to him later, Robinson’s reply had the ring of a reprimand: "I think I know a hawk from a handsaw."

Discernment was sufficiently widespread to ensure an enthusiastic reception for Docherty and that was a particular boon to our family, for whom it would always be the most personally involving of Willie’s novels. Seeing it as to any serious degree collectively biographical would, of course, have been not just grossly inaccurate but an insult to the scope of his intentions. Yet Docherty was plainly rooted in his upbringing among us and, more extensively, in the accumulated lore of the family – tales of our mother and father and their kin, of cousins and uncles and aunties, of neighbours and friends and acquaintances and vividly incarnated fringe figures. When our household wasn’t a fairly clamorous debating chamber (though never inclined to fall out in a major way, we were a relentlessly disputatious bunch, on any subject the world suggested to us), it was likely to settle into a quiet and lengthy session of story-telling. Willie and I, as the youngest in the group, with slightly less than three years separating our ages, happily punctuated the role of avid listeners with requests for anecdotal elaboration.

Many of the most compelling narratives concerned High Street, near Kilmarnock town centre, where I spent the first two years of my life crammed with my parents and older brother and sister into a tiny flat with set-in beds in one of the three-storey tenements that constituted standard accommodation there. We had already moved to the first of our council houses (part of an estate, or ‘scheme’ as we called it, close to the northern edge of the burgh) when Willie was born. So he had no direct experience of living in High Street, and the imprint of its day-to-day existence on my consciousness was obviously negligible, although I felt a tingle of affinity when I returned often as a boy for an overnight stay with a childless couple who had been our neighbours in the tenement and wanted to keep a connection. Like Willie’s, however, my abiding impressions of High Street were formed by the verbal records of our elders, their evocations of communal vibrancy and defiant humanity maintained amid besieging poverty and the disintegration of dreams that never had a plausible foundation. Their testimony did not gloss over the squalor to which lives could descend there, or the instances of behaviour too reprehensible to be excused by oppressive circumstances, but they told, too, of the majority’s acceptance of a code of conduct that was no less nuanced or demanding for being tacitly defined. By auditory osmosis, our developing sensibilities came gropingly to embrace the High Street of an earlier time as a microcosm of the best and the worst in the life of the industrial poor, at least as it was lived in the west of Scotland.

The lasting impact of all of that on Willie is manifest throughout Docherty, which exemplifies his refusal to shy away from what he saw as the serious writer’s obligation to attempt to imbue the specific with something more universal. His attitude to place names in the book is interesting. He calls Kilmarnock Graithnock (though the Scots word graith can have multiple applications, we may be sure he was thinking of its definition as the tools or equipment needed for work) but there is little further evidence of such minor obliqueness. We are acquainted not only with the actual names of Kilmarnock streets but with their precise relationship to one another as Willie knew them – High Street running into Soulis Street then Fore Street (the Foregate), leading to the Cross, traditional centre of the town; Union Street offering a right turn towards Boyd Street and so on. Kay Park plays itself and so does the river separating it from High Street, and the dark grey hulk of the long-gone infirmary, its aspect uncompassionate as a prison’s, is observable on its hill only from the vantage points it once was. Did he use accurate topography as mooring for his imagination or perhaps as a sustained pulse of respect for the realities he was transmuting to fiction? Or did he simply decide that putting his cast on location, rather than on a set constructed in his mind, gave him more freedom to concentrate on what his actors were doing, thinking and feeling?

Inevitably, the tangibility of the terrain of Docherty raises the question of how closely its characters resemble real people, starting with members of our family. The answer, as is the case with most fiction, is that composites whose source elements are identifiable mingle with a throng of figures who are creative inventions. And if there are blatant differences between the story of the Dochertys and the story of our branch of the McIlvanneys, the links and the echoes are unmissable. The book begins with the scenes around Conn’s birth at the end of 1903, which was pretty much when my father arrived in the world. His name was William but his father had been Con and he was widely known as Young Con. However, the character in the novel who is drawn most clearly (if by no means comprehensively) from my father isn’t Conn but his sire, Tam Docherty. Like Tam, my father stood ‘only five-foot fower’ but he was a strong, hard wee man with firmness of principle and will, somebody who made it easy to understand why my mother could say: ‘When he was there, I never knew a moment’s fear.’ Again like Tam Docherty, his relinquishing of Catholic faith encouraged in him a pragmatic ecumenicalism. Betty and Neil went to St Joseph’s school but Willie and I were subsequently enrolled at the Protestant primary serving our scheme, with traffic dangers cited as a justification the Pope doubtless found unimpressive.

There were other similarities, large and small. My father worked in the pits for some years, he was vehemently socialist and he was capable of outstripping his sons physically with the feat of a prolonged handstand on a chair that Tam employs to counter Angus’s arrogance in one of the domestic episodes in which Docherty charges the trivial with significant tension. But, in contrast with Tam, my father never allowed his disappointments to deflect him from the unprissy teetotalism that had become a creed as a result of the devastation-by-drink he witnessed at close quarters in his childhood. Having presumably placated the ghost of Keir Hardie, through the latter part of his short life he intoxicated himself with quixotic dreams of entrepreneurial success.

Enterprises as disparate as bookmaking, operating a second-hand shop and efforts at the mass rearing of chickens in our back garden invariably foundered against economic imperatives, and left my mother patiently clearing up the debris. Helen, or Nellie, McIlvanney (née Montgomery) wrought the kind of miracles with scant household finances that Willie attributes to Jenny Docherty, forever sacrificing her own comfort in the interests of her children, often giving us cause to mistake her for a saint with cardboard in her shoes. Despite having begun toiling in a textile mill at an obscenely young age, she had a good level of literacy and was a lover of poetry. In the attractive copperplate script she had acquired during her truncated schooling, she produced accounts of her memories to help Willie with his writing. Her High Street chronicles must have been especially useful as he moved through Docherty.

What emerged in 1975 from the combined powers of his intellect, imagination and spirit must certainly be ranked among his finest works. Allan Massie, himself a distinguished novelist as well as a respected critic, credits Willie with the remarkable achievement of having written not one masterpiece but two, Docherty and The Kiln. There is no demurral from me but I would also put a book of a very different stamp, Laidlaw, in the frame. Yet none of Willie’s novels moves me more than Docherty does. Perhaps its themes and personal resonances make that natural. Revisiting it shortly after his death in December 2015, I was back in his company, remembering how much we had shared.

We slept in the same bed for years; joined in a thousand banal boyhood sorties that we fantasised into adventures; participated in myriad over-populated football games that started in the morning and – with hunger imposing a shift pattern on the teams – kept going until darkness was total; eagerly widened our vistas through reading. And, always and inexhaustibly, we fed each other’s flights of fancy about what lay ahead for us. Nothing in the professional area of Willie’s future would mean more to him than the challenge (resolutely met) of championing the relevance of a multitude of unsung working-class lives. The profoundness of his belief in that endeavour is conveyed in a poem of his I quoted when memorial tribute was paid to him in the Bute Hall of Glasgow University:

In any street an epic, any room

Strange stories never told, testaments dumb.

The richness overwhelms. A chance remark

Can touch new land, unload another ark.

Transactions of small change will sometimes yield

Coins of a minting you have never held.

Break any casual stone and find strange veins.

The colours blind. The anecdotes will range

Through wild geographies of spirit, form

Plain men with unknown flowers in their arms.

In each face new horizons, any day

An archaeology more rich than Troy.

As I said in the Bute Hall, when it came to the digs associated with such archaeology, we all benefited from having Willie’s hand on the trowel. Docherty is the proof of that.

Docherty by William McIlvanney is published by Canongate Canons, priced £8.99.