Ion Trewin: Guiding hand behind lauded big-name biographies who became the literary director of the Man Booker prizes

As editor, publisher, biographer and guide to authors from Michael Palin to Judi Dench, Trewin knew every art and skill required to turn a life into a narrative

Trewin: ‘A bookman of capacious humanity’ (Man Booker Prize/PA)

In 2006, after he had retired as editor-in-chief of the publishers Weidenfeld & Nicolson, Ion Trewin not only took over as literary director of the Booker Prize Foundation. Trewin, who has died of cancer aged 71, combined this new brief as overseer, spokesman, mentor and fire-fighter for the Man Booker awards with a "special" (ie visiting) professorship in the School of Politics at Nottingham University.

With Professor Alex Danchev, he set up a new course in political biography, which itself won an award. Trewin and Danchev – who found in his teaching partner "a bookman of capacious humanity, a rare bird" – set the first batch of students an assignment. It was to write, as if for the "slab" of a quality newspaper, a "forward obituary" of Tony Blair.

In October 2014, the announcement of Trewin's illness at the Man Booker award ceremony brought a spontaneous wave of sadness and shock. His many colleagues and friends within and beyond the book world will regret that, so soon after, Trewin's own obituary can no longer sit in the "forward" file. As editor, publisher, biographer and guide to authors from Alan Clark and Michael Palin to Judi Dench and Edna O'Brien, he knew every art and skill required to turn a life into a narrative. Now his own story has to pass into others' hands.

Trewin's role as the public face of the Man Booker Prizes capped a career which had sought to marry literature and commerce, quality and popularity. His father had been a proud Grub Street veteran: the Cornish journalist, critic and dramatist JC Trewin, long-serving theatre critic of The Observer.

Born in 1943 and educated at Highgate School, Ion Trewin did not go to university but returned to the West Country to follow the family business as a reporter on the Independent and South Devon Times in Plymouth. From Devon he went to Fleet Street, joining the Sunday Telegraph in 1963 and The Times in 1967. After five years on The Times Diary, two as editor, he became the paper's literary editor from 1972 to 1979. There he created a page for paperback reviews: commonplace enough now, but a revolution then.

Next came a still-unusual poacher-to-gamekeeper move. Trewin quit journalism to become senior editor at Hodder & Stoughton, then (in 1985) the company's editorial director. Having served as the youngest chair of the Booker Prize jury in 1974, as a publisher he shaped and edited the documentary novel that gave the competition its best-selling winner: Thomas Keneally's Schindler's Ark in 1982. Like every other editor, Trewin had to surf the wave of consolidation and conglomeration that saw the – allegedly – genteel business of London literary publishing become a branch-office of the worldwide entertainment industry. This new climate called for a new skill-set, in which even books of distinction demanded the hard sell. As with the Booker Prize, he mastered the knack of balancing excellence and accessibility, the cash and the cachet.

In 1992 he transferred to the Orion Group, one of the new breed of umbrella publishers that now sheltered famous names. Trewin became publishing director and then managing director of Weidenfeld & Nicolson, which had kept its reputation not only for fiction, but inside-track biography and autobiography. From Dench to Palin, the fact that quite a few of Orion's "celebrity" authors also won applause for their writing owed not a little to Trewin's guidance.

At Weidenfeld, Trewin began his best-selling collaboration with the maverick Conservative politician Alan Clark and his wife, Jane. Published between 1993 and 2002, the three volumes of Clark's diaries caused amusement, alarm and even scandal with their well-spiced mixture of political and personal indiscretion. Some critics worried that Trewin's own amiability had whitewashed a nasty piece of work. As editor, after Clark's death in 1999, Trewin once had to transcribe a passage with explicit details about one of the diarist's many extra-marital affairs. He presented it to Clark's widow with a Post-it note inscribed "health warning". Jane Clark left the decision on whether to publish to Trewin. He did so.

Their bond of trust led to Trewin's appointment as Clark's authorised biographer. Almost as much an admiring portrait of Jane herself as a warts-and-all chronicle of Alan's misadventures in sex and politics, Alan Clark: the Biography appeared in 2009 to brisk sales and widespread critical acclaim.

By then, Trewin had left Weidenfeld to steer the Man Booker prizes as the successor to Martyn Goff (who himself died last month). Less feline, more emollient than Goff, his style there not only drew on the tact, charm and diplomacy that colleagues came to expect from his genial presence. For the Booker job involved not only the cat-herding task of choosing the judges and keeping them on schedule and in line; it also meant defending the prizes in the teeth of the annual squalls of controversy over shortlists, winners and absentees.

On his watch, the Man Group sealed its long-haul commitment as sponsor of the awards. The biennial Man Booker International Prize established itself as a lifetime-achievement honour with a global remit. And the annual prize contentiously opened its doors to the whole of the English-writing world, Americans included.

Meanwhile, Trewin had to park his own tastes at the door and safeguard the integrity of the judging process. As he wrote, "Sometimes I must bite my tongue: Oh, how much I would like to add my two penn'orth of opinion… My job now is to advise, to remind judges where necessary of the rules, and to keep an eye on the clock." He prepared the ground for these official sessions with informal meets for each year's panel, often at the Garrick Club. True to the Grub Street spirit, the aura of gossip, speculation and even feuding that always surrounds the Man Booker jamboree is meant not only to titillate onlookers but to lure shy new readers into a place where they will discover and enjoy first-rate fiction.

Trewin's other book-world commitments stretched from the Cheltenham Literature Festival to the National Academy of Writing, which offers conservatoire-style practical training to aspiring authors. All of these activities kept faith with the Johnsonian ideal of literature as at once trade, craft and art, open to everyone but in nobody's pocket. He is survived by his wife, Sue, his children, Maria and Simon, and four grandchildren.

Boyd Tonkin

Ion Trewin, publisher and author: born London 13 July 1943; married Sue Merry (one son, one daughter); died 8 April 2015.