The Secret Lives of Somerset Maugham, By Selina Hastings

Some declines in literary reputation are steep; others still steeper. If William Somerset Maugham's 60-odd books are today far less read and even less often acclaimed than in his lifetime (1874-1965), his advocates may take some comfort: the demolition job he did to the reputation of Hugh Walpole has proved terminal. Maugham's ink was frequently mixed with poison, as revealed in his fictional portrayal of the ingratiating, insincere popular novelist Walpole in Cakes and Ale (1930).

Today, Maugham's own standing is harder to calibrate. True, he remains the most filmed of all fiction writers, surpassing Conan Doyle for the number of screen adaptations. Recent celluloid releases include Up at the Villa and a third version of The Painted Veil. This, though, could leave him more brushed-against than read or loved.

Of the novels, the two autobiographical bestsellers are still mentioned – Of Human Bondage (1915) and Cakes and Ale, though to me these can be in every sense painful reads. The Gauguin-inspired The Moon and Sixpence (1919) may last too, though all three feel prolix against less familiar titles like The Narrow Corner (1932) and an Indian novel, The Razor's Edge (1944).

Prose style is invariable the least compelling thing in Maugham. Like the architect Borromini, he flourished only under containment. The less space he had, the more dramatically he created. The stories certainly should survive. They illustrate - as Maugham knew, having copied his technique carefully from Maupassant - that nobody writing in English penned stories as sure and shapely in composition. "Rain", one of his earliest and best tales set in the Far East, won instant acclaim and was endlessly anthologised and adapted. Its royalties alone could have financed Maugham's beloved, elaborate Cote d'Azur home, the Villa Mauresque, where he first lived with the dashing American reprobate Gerald Haxton, who had been banned from the UK following a homosexual scandal.

After Haxton's death, and a period of near-delirium for Maugham, a replacement, Alan Searle, moved in. Searle kept his nickname, "Bronzino Boy", longer than his progressively pudgy physique strictly merited. Maugham, contrastingly, was lithe, fit and agile well into his eighties. He kept on 13 full-time staff, catering to the author's every need, and the many more readily announced by his many visitors.

Maugham was disciplined yet modest in his daily workload. He reasoned three hours a day should suffice, since it had for Charles Darwin. As the shelf full of titles to his name indicates, Maugham was rarely blocked. Novels, stories and plays poured from him. Revisions were minimal.

He placed himself "in the very front row of the second rate" publicly. He grew frustrated at being overlooked or dismissed by critics and peers - Bloomsbury especially. Maugham thought snobbery lay behind it, simply because his books flew off the shelves.

He also angled for official recognition, in one unwise gamble turning down a knighthood since he had his eye on the superior Order of Merit. Maugham took to snobbery, and was charmed by royalty, nobility and, latterly, by sheer wealth. He played to his public. On stage, he gave them what they wanted: an adultery, a confidence, a betrayal. He was bored long before he gave up writing plays. Today, only the 1920s dark comedy The Circle is much performed.

Maugham married Syrie, and sired a daughter Liza, to whom he demonstrated anything from open indifference to outright disgust. He insisted to nephew Robin – as queer and rapacious as his uncle – on the need for discretion, and on the duty to produce an heir. Yet the marriage to Syrie, though a useful fig-leaf, had huge flaws. It made sizeable inroads into Maugham's royalties, but gnawed away still more vitally at his emotional reserves.

Syrie loved, and demanded to be loved in return. If Maugham's youthful bisexuality was genuine, by mid-life he found all women a turn-off and most a social irritant. He was intrigued by Oscar Wilde, and befriended many of the Irishman's surviving circle. His own trajectory shows what Wilde might have become had he avoided disgrace.

Maugham's achievements were, necessarily, also tributes to the power of the closet. Like Walpole, he kept his sexual appetite a private concern, one that must not come near the work (though Gore Vidal thought The Narrow Corner a "crypto-fag" novel, and there are undercurrents everywhere).

He admitted he had little imagination. Friends complained when he stole their stories, characters, behaviour, backgrounds and even names. To the hostile, he was largely a transcriber, and always morally neutral as author or narrator; so, a "cold fish".

Aged 73, he sat for Graham Sutherland, who produced a portrait so mean, embittered and unforgettable that it risks becoming more famous than Maugham's novels. The author persuaded himself into buying it, but was perturbed by its potency. It was secreted away. The story of a man tormented by a portrait of himself, revealing the crevices and wrinkles connoting decadence and corruption: it would have been a great subject, but The Picture of Dorian Gray had been written.

Selina Hastings thinks it "safe" to predict an upturn of interest in Maugham. Still, her own judgments are intelligently nuanced and not entirely positive; "if flawed" is a recurrent formulation. Ted Morgan did groundwork in the many interviews for his 1980 biography, as Hastings always properly allows. Her superior, marvellously rich synthesis of so many resources, however, produces a narrative that is strikingly clear yet never reductive. It's a gripping, often sensational account of a singular life, gaining pathos in its closing descriptions of the senile Maugham's manipulation by Searle, leading to his final, uncharacteristically ungentlemanly and bilious disclosures, dished up for lucre to the Sunday Express, but refused by Maugham's publishers as an act of loyalty.

Richard Canning's life of EM Forster is out soon from Hesperus Press