The adventures of the most famous detective in the world, Sherlock Holmes, have been adapted to various forms of media for over a hundred years, and that's because no one fully owns the rights to the Great Detective, and here's why. Created by Arthur Conan Doyle, Sherlock Holmes first appeared in A Study in Scarlet in 1887 and quickly became a hit. In total, there are four novels and 56 short stories documenting the cases solved by Holmes and his friend and biographer John Watson.

Sherlock Holmes adaptations a few years back, and while it might have been just a coincidence, the truth is that the rights to the characters and the stories have made adaptations a lot easier.

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The rights to Sherlock Holmes, the stories, and the rest of the characters have gone through a roller coaster: they expired in the United Kingdom and Canada in 1980, were revived in 1996 and expired in 2000. Since then, Doyle’s works are in the public domain in those territories. In the U.S., however, it was a very different story. In 2013, Leslie S. Klinger, lawyer and editor of The New Annotated Sherlock Holmes, filed a lawsuit against the Conan Doyle estate asking the court to acknowledge Holmes and company were public domain in the U.S. This case prompted the question: does copyright on a character persist even after the works with that character have fallen out of copyright?

The Conan Doyle estate argued that, although the stories were in the public domain, there were others still under copyright (such as The Case-Book), and so Sherlock Holmes was still also under copyright. The court ruled in Klinger’s favor, meaning that stories and characters from Holmes’ universe are now in the public domain in the U.S. – except for nine stories featured in The Case-Book, minus “The Adventure of the Mazarin Stone”, “The Problem of Thor Bridge”, and “The Adventure of the Creeping Man”. The rights to those stories will expire between 2020 and 2023.

However, because those nine stories serve as the origins for some key character elements, such as Holmes and Watson's genuine friendship, and Holmes' own development as a human, the adaptations do still need to seek permission from the Doyle Estate. Nonetheless, being in the public domain certainly makes adaptations easier, and Sherlock Holmes’ popularity is such that he will remain one of the most beloved characters in pop culture no matter how many versions are made for TV, film, stage, and more.

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