In the 1960s William Buchan — the second son of John Buchan, 1st Baron Tweedsmuir and the author of The Thirty-Nine Steps — said of his father: “The more I read his books again, the more I admire them. They have a moral strength and purpose.” Like several members of his family, William Buchan shared John Buchan’s literary gifts, producing several novels, poetry, a memoir and an admired book about his father while also pursuing a career in publishing and public relations.

William de l’Aigle Buchan was born in 1916 and grew up in Oxfordshire. His mother was a Grosvenor and a close relation of the Duke of Westminster. From an early age he read voraciously, and his father would often read his books out loud as he worked on them. “He made no fuss about writing,” William recalled. “We could run in and out while he worked. And he was always ready to stop and help us as soon as we started writing for ourselves.” For William this, initially, was mainly poetry.

He was educated at The Dragon School, Oxford, Eton and New College, Oxford. He left university early; when The Thirty Nine Steps was being made into a film, he met Alfred Hitchcock, and he went to work as his assistant.

During the war Buchan joined the RAF Volunteer Reserve, becoming a squadron leader. At the end of the war he joined the Pilot Press in London and continued to write — by the early 1940s he had had several short stories published in the US, and at the age of 24 he published a 10,000-word biography of Winston Churchill. He also produced, in close collaboration with the Air Ministry, The Royal Air Force at War, an account of the daily work of the RAF’s various sections.

Times Archive, 1940: Obituary: Lord Tweedsmuir

Novelist, lawyer, publisher, historian, soldier, biographer and proconsul, John Buchan had a career as varied as it was distinguished

• Leading article: John Buchan

In 1943 Buchan published a book of short stories, The Exclusives, and in 1952 a volume of Personal Poems, many inspired by his RAF experiences and reflecting on the loves and frustrations of that period of this life:

Grinding and dusty, sour, enchained in wrong

(Not in our hands to alter), profitless, mad,

Ruined indeed the years, so short, so long,

Which have come like a fog between us and the joys we had.

(From A Water Party, 1942)

The TLS called Buchan’s voice “winning and sincere”, and noted: “In writing to please himself, he will please others too, for his unselfconcious sympathies are easy to share, his young man’s experience corresponds with that of half his generation, his turn for verbal music is quietly refreshing, and everywhere competent.”

Three years later he wrote Kumari, a lush, complex novel about the experiences and romances of a young man in 1930s India. It was praised for its powerful evocation of place: it tells the reader as much about India and the course of British rule “as a hundred official publications”, wrote one reviewer, “or, it might be added, a dozen travel books”. In 1961 Buchan published his first thriller, Helen All Alone, the story of a charming Englishwoman sent in 1950 as a secret agent to resolve a tricky problem in the Balkans. Buchan wrote it deliberately to his father’s plan, and it was indeed much in the vein of his father’s novels. But it differed significantly, too, being, it was thought, the first secret service novel with a woman as its main character — a fact not appreciated by The Times, which advised: “Women in a thriller should be decorative, not pivotal.” The TLS, by contrast, praised Buchan’s sensitivity to atmosphere and scenery.