A Study in Scarlet was written in 1886 and is the first appearance of Sherlock Holmes and Dr Watson, who would become the most famous detective duo in popular fiction.
The story, and its main characters, attracted little public interest when it first appeared.
Only 11 complete copies of the magazine in which the story first appeared, Beeton's Christmas Annual are known to exist now and they have considerable value.
Although Sir Arthur Ignatius Conan Doyle wrote 56 short stories that featured Sherlock Holmes, A Study in Scarlet is one of only four full-length novels.
A Study in Scarlet was the first work of detective fiction to incorporate the magnifying glass as an investigative tool.
The character of Sherlock Holmes has been portrayed by over 100 different actors in theatre, on radio, in film, on audiobook and on television.