Pooley says that its approval comes down to the quality of the writing, and if the writer stays “true to Doyle’s depiction of Holmes’s and Watson’s characters” – meaning they don’t mind if Cumberbatch’s Holmes lives in modern London, or if Holmes and Watson are women, as in HBO Asia’s Miss Sherlock.īut not all spin-offs are equal in the eyes of Conan Doyle’s estate, and writers can run into quicksand when reimagining the beloved detective. The estate has authorised Horowitz’s sequels and Lane’s stories, but most Holmes adaptations come without the estate’s stamp of approval – not that that appears to put readers off. “Instead she focused on giving her approval to those Holmes pastiches which were well-written and did not stray too far from Doyle’s characterisation. In the end she realised this was a fruitless exercise,” says Richard Pooley, director of the Conan Doyle estate and step- great-grandson of the author.

“My step-grandmother, Dame Jean Conan Doyle, tried hard to stop the world doing what it liked with her father’s fictional characters.

Nicholas Meyer’s forthcoming The Return of the Pharaoh is drawn “from the Reminiscences of John H Watson, MD”, while Bonnie MacBird’s The Three Locks, a new Holmes adventure, is out in March. James Lovegrove has combined the worlds of Holmes and HP Lovecraft in the Cthulhu Casebooks. Star basketball player Kareem Abdul-Jabbar has written novels about Holmes’s older brother Mycroft Nancy Springer wrote the Enola Holmes books, giving Holmes and Mycroft a younger sibling.

There are Anthony Horowitz’s sequels, or Andrew Lane’s tales of a teenage Holmes. Photograph: Alex Bailey/Netlfix/APĪnd then there are the endless literary takes. Henry Cavill (left) as Sherlock Holmes, with Millie Bobby Brown as Enola and Sam Claflin as Mycroft in Netflix’s Enola Holmes.

The sign of the sherlock holmes