Writer Dick Francis, famous for his horse racing-based crime novels, has died aged 89, his family has said.
Francis, who wrote more than 40 best-selling novels during his career, was also champion jockey in the 1950s and the Queen Mother's jockey.
He first published his autobiography in 1957, and his first thriller, Dead Cert, followed five years later.
Francis's most recent works, including Dead Heat and Silks, were co-authored by his son Felix.
Mr Francis said he was "devastated" at the loss of his father, who produced a novel a year during his long career.
"We share in the joy that he brought to so many over such a long life. It is an honour for me to be able to continue his remarkable legacy through the new novels," he added.
A Buckingham Palace spokesman said the Queen would be "saddened" by the news.
Former racing commentator Sir Peter O'Sullevan called him "a very good mate" and said: "I particularly enjoyed reading his novels and found him a wonderfully efficient author."
Former jockey John Francome said: "He was a lovely person who always had a sparkle in his eye and he had a wicked sense of humour.
"I remember we used to laugh out loud about the old times."
Francis went on to sell some 60 million books worldwide and his novels were published into 20 languages.
His works were also regularly featured in volumes of Reader's Digest condensed books.
They were all written in the first person and were meticulously researched and written in longhand.
Francis went on to win numerous accolades for popular fiction in his genre, including Crime Writer's Association lifetime achievement award in 1996.
He was awarded a CBE in 2000 for services to literature.
During his racing career, Francis's most famous moment was when his horse, Devon Loch, fell when he was close to winning to 1956 Grand National.
In 2006, Francis said of the famous incident: "It was a terrible thing but I look back on it now and I can say that if it hadn't happened I might never have written a book, and my books have certainly helped keep the wolf from the door."
After he retired from the saddle, Francis was the Sunday Express racing correspondent for 16 years.
He spent his final years in retirement in the Cayman Islands and his family said he "died of old age".
A private funeral is due to be held in the Caribbean with a memorial service in London at a later stage, a spokesman added.
The next novel co-written with his son is due to be published in the autumn.