Sir Arthur Ignatius Conan Doyle (22 May 1859 - 7 July 1930) was a Scottish physician and writer who is most noted for his fictional stories about the detective Sherlock Holmes, which are generally considered milestones in the field of crime fiction. He is also known for writing the fictional adventures of a second character he invented, Professor Challenger, and for popularising the mystery of the Mary Celeste. He was a prolific writer whose other works include fantasy and science fiction stories, plays, romances, poetry, non-fiction, and historical novels. The traditional Sherlock Holmes canon consists of four novels and fifty-six short stories collected. In this book: Novels A Study in Scarlet (published 1887) The Sign of the Four (published 1890) The Hound of the Baskervilles (serialised 1901-1902 in The Strand) The Valley of Fear (serialised 1914-1915) Short stories The Adventures of Sherlock Holmes (published 1892) The Memoirs of Sherlock Holmes (published 1894) The Return of Sherlock Holmes (published 1905) His Last Bow (published 1917)