Watership Down author Richard Adams has died aged 96, a statement on the book's official website has said.
He "passed away peacefully" at 10pm on Christmas Eve.
The statement, issued on Tuesday, said: "Richard's much-loved family announce with sadness that their dear father, grandfather, and great-grandfather passed away peacefully at 10pm on Christmas Eve."
Watership Down, the tale of a group of young rabbits escaping from their doomed warren, was conjured up by civil servant Richard Adams during bedtime story-telling sessions.
His daughters, Rosamond and Juliet, adored hearing the rabbits' adventures, set in the Hampshire countryside. And at their request, aged 52, he put pen to paper.
The story was rejected by six publishers, all concerned that older children would not want to read about rabbits and that its dark themes were too "adult" for younger children.
But Adams maintained it was a tale for all, from those "aged 8 to 88", and he was proved right when it was published in 1972.
It went on to become a best-selling classic and was adapted into a 1978 cinema hit, directed by the author's good friend Martin Rosen.
Adams later admitted the depiction of his rabbits was not quite as he had imagined.
But the animated film and its accompanying theme song Bright Eyes, sung by Art Garfunkel, became an enduring family favourite.
Adams stumbled into a career as a writer. Born May 9 1920, and raised in Berkshire, he enrolled at Worcester College in Oxford in 1938, but when war broke, enlisted in the Royal Army Corps.
He returned to complete his studies, gaining a degree in modern history, before finding work as a civil servant in the ministry of housing and local government in 1948.
Adams married his wife Elizabeth in 1949, his neighbour's daughter, who he had met when she was 17. In his nineties, he still referred to her as the "the girl next door".
The success of Watership Down allowed Adams to become a full-time writer, penning several novels, including Shardik in 1974, a fantasy novel about a wounded bear, which he described as his favourite work, but which failed to replicate Watership Down's success.
The author's interest in animals extended beyond his literary works and he was president of the RSPCA from 1980 to 1982.
In 1996, 24 years after his first novel, Adams published its sequel, Tales From Watership Down, a collection of 19 short stories which allowed readers to rekindle their relationship with the much-loved characters.
In his later life, he expressed regret that he had not realised his talent sooner, saying: "If I had known earlier how frightfully well I could write, I'd have started earlier".
Adams spent his later years with his wife at their home in Whitchurch, Hampshire, retaining a passion for reading and writing.