Sir Simon Hornby: Scion of the WH Smith dynasty who revitalised the company in the 1980s

With his commanding height – he stood 6ft 3in – his perfect manners and his tendency to wear slightly foppish clothes, Simon Hornby always looked what he was at heart – a latter-day embodiment of Renaissance Man.

He was born in London, but grew up at Pusey, his parents' lovely 18th-century house in Berkshire, where his father, Michael, kept a stable of high-class hunters, and his mother, Nicolette, created a memorably beautiful garden. His career at Eton was undistinguished – except that he acquired elegant, spiky italic handwriting, taught by the drawing master Wilfrid Blunt. After National Service in the Grenadiers he went up to New College, Oxford, where his main recreation was riding. A good horseman across country, he hunted fearlessly with the Heythrop and with the university Drag Hounds, whose Master, Edward Cazalet, quickly became a close friend.

Pusey was the scene of tremendous summer parties, and of cricket matches between two scratch sides, on which a good deal of money was punted. At the end of one hard-fought game the scorer, Michael Hornby – a man of great precision and business prestige – announced that Side A (captained by Colin Ingleby-Mackenzie) had won by three runs. A recount, however, showed that Side B (captained by Simon) had won by five runs – and the recriminations, imbibing and hilarity which followed were prodigious.

In December 1967 Simon and Edward's sister, Sheran, went off for a holiday in Mexico. They had known each other for eight years, but now suddenly they fell in love and decided to get married the following summer. The wedding took place at the Cazalets' home in Kent, and to it Sheran invited one of her oldest friends, the actress Elizabeth Taylor.

The service was due to start at 11.30am, but because the star was habitually late, Sheran told her that kick-off time was 10.30am. Everyone was amazed when for once she appeared punctually, and no one was more startled than the landlord of the local pub, the Chaser, who suddenly found Elizabeth Taylor, Richard Burton and Noël Coward confronting him across his bar in search of an early stiffener.

Simon never had to search for a job, because heredity handed him a central role in WH Smith, the nationwide bookseller, stationer and newsagent, where his grandfather and father had both been partners before him. From a traditional start as a trainee in 1958, and a lowly first post as stationery buyer in the Sheffield wholesale warehouse, he rose through the ranks to become retail director, managing director and chairman.

As the firm's chairman from 1982 to 1994 he sought to energise the sleepy giant by diversifying. At first everything went well, but later some of his projects faltered, and parts of the business had to be sold off. Overall, he was judged to have played a significant role in moving the company forward.

Although he was dedicated to the welfare of the family firm, and gave it his best, he also held an extraordinary range of other appointments – with the bankers Lazards, Pearsons and Lloyds, with the National Trust, the Victoria and Albert Museum, the British Museum, the Royal Society of Arts, the Design Council, the Association for Business Sponsorship of the Arts, the Book Trust and the National Literacy Trust. As President of the Royal Horticultural Society from 1994 to 2000 he precipitated a major row by insisting that the Lindley Library be moved from Wisley to London.

He once told a friend that he believed emphatically that people should do what they want in life, "because they'll nearly always do that best and enjoy doing it". He himself, always approachable, flung himself into everything he did with huge enthusiasm. His knowledge of the arts was exceptional: armed with good taste and a first-class eye he became a scholarly expert on the art, culture and history of Venice, knew almost all the major gardens of the United Kingdom and France, read widely and amassed a fine collection of modern watercolours. A generous host, he took a deep interest in food and wine and was a skilful cook, master of many exotic sauces and soufflés.

In private he was no mean entertainer. A wonderful raconteur, and more-than-competent at the piano, he loved performing Gershwin and Kern favourites with Sheran's nephew Hal Cazalet, the opera singer. He could also be persuaded to bring out ridiculous old music-hall turns:

A. I say, I say, I say! My old man's taken some plums down the palace.

B. Woss he done that for, then?

A. Well – don't it say in that old song "Send her Victorias"?

He and Sheran never lived in Pusey itself, which was too large, especially as – to their great disappointment – they remained childless. Instead, they moved into Lake House, a smaller dwelling close by, and there Simon deployed the knowledge gained from his mother to create a stunning garden.

All through his life he was supported by devoted retainers, first by his father's head groom at Pusey, Lennie Demain, who had been evacuated from London with his family during the Blitz and had never returned. A later stalwart was Blondie Bonacker, a former prisoner of war who became the Hornbys' indispensable butler and factotum and married an English wife but never lost his German accent.

One of Blondie's finest moments came at Lake House, when, as the party was changing for dinner, cries of distress emanated from upstairs, where a woman of substantial dimensions had got stuck in the bath. Rushing to her rescue, Simon and Blondie found that she had let the water out and the cry went up, echoing the launch of the Mulberry harbours in 1944, "Turn on the taps and float her off!"

In 1992 the Hornbys moved to the Ham, an 18th-century house on the southern outskirts of Wantage. Here, he and Sheran entertained an ever-increasing mix of friends, to the delight of anyone lucky enough to be invited. Outside, he created another exceptional garden, its acres of immaculate lawn fringed by water and commanding views of the distant Berkshire downs. He put in hundreds of trees, knew the Latin name of every plant he introduced, and constantly experimented to see what species did best in particular types of soil.

His last years were clouded by the onset of Parkinson's disease, and by the progressive deterioration of his eyesight, which made it increasingly difficult, and then impossible, for him to read – an awful deprivation for someone who had spent much of his life surrounded by books. Buoyed up by Sheran's ever-loving care, he bore this misfortune with fortitude, and to the end he drew inspiration from his garden, for in spite of his increasing disability, his love of trees, plants and flowers never waned.

Duff Hart-Davis

Simon Michael Hornby, businessman: born London 29 December 1934; Director, WH Smith 1974-94, Chairman 1982-94; married 1968 Sheran Cazalet; Kt 1988; died Wantage, Oxfordshire 18 July 2010.