Sir Arthur Conan Doyle died in 1930, but his most famous work—stories about the English detective Sherlock Holmes—has lived on. Thanks to copyright law, those stories have also continued to benefit Doyle's heirs for the past 84 years. Every time someone wanted to write a story or film a movie about Sharlock Holmes, the Doyle estate would collect a fee. A legal ruling announced this week, however, has set Holmes free: the character and all his companions (as penned by Doyle) are now in the public domain.

The legal case of Klinger v. Conan Doyle Estate that settled the claim actually rested on an interesting issue, whether a copyright claim can persist on a character even if the works depicting that character have fallen out of copyright. The defense of the Doyle estate went something like this: sure, Arthur Conan Doyle's stories are now at least 90 years old, but other stories about Sherlock Holmes are still under copyright, therefore Sherlock Holmes is still under copyright.

Judge Richard Posner didn't buy the argument, and he ruled that Sherlock Holmes, the character, is now in the public domain.

Part of the motivation for the Judge's decision, says Molly Van Houweling for the Authors Alliance, was a consideration of what the larger ramifications of extending the copyright on Holmes would have on art in general. Holmes' lasting popularity is a rarity among fictional characters—most fall out of favor within years, not decades. Creating a longer term on copyright for characters would reduce the number of works flowing into the public domain. This, in turn, would make it more difficult or more expensive for future artists to work, since a great deal of art draws on earlier works.

There's another interesting facet to the case, too. The Doyle estate's argument hinged on the idea that Sherlock Holmes was a complex and defined character, one whose characteristics were set down by Doyle. But that argument, say Parker Higgins and Sarah Jeong in their 5 Useful Articles newsletter, really just isn't the case:

Posner's opinion has much to commend, but one area it does not delve into is how the character of Sherlock Holmes—as we know him—is the construct of many authors, artists, and even film-makers. As Authors Alliance co-founder Molly Van Houweling points out, the phrase "elementary, my dear Watson," never appears in any of Doyle's works. And Doyle himself never described Holmes wearing his signature funny hat, this pop culture impression of the detective came about through a series of others' interpretations—first, in a few original illustrations by Sidney Paget, which probably influenced the stage actor William Gilette's depiction of Holmes, whose photo inspired American illustrator Frederic Dorr Steele to consistently draw the character in a deerstalker cap, an artistic choice that made its way into a number of cinematic versions.

So what adventures should Sherlock and Watson get up to next? It's time to get your fan fiction juices flowing.