Why does actor Benedict Cumberbatch cut such a dash as British literary detective Sherlock Holmes?

That’s elementary, according to genealogy website Ancestry.com. Cumberbatch is distantly related to author Arthur Conan Doyle, who created the brilliant but quirky sleuth some 130 years ago, the website said on Sunday.

Cumberbatch, 40, star of the Emmy award-winning BBC TV series, Sherlock, is a 16th cousin, twice removed of Doyle.

The two are related through 14th-century English nobleman John of Gaunt, who, according to records, was Cumberbatch’s 17th great-grandfather and Conan Doyle’s 15th great-grandfather, Ancestry researchers said.

The chance to play a character created by a relative

John of Gaunt, born about 1340, was a son of England’s King Edward III, meaning that Cumberbatch and Conan Doyle also have a distant royal connection.

“How rare that an actor in a major series has the chance to play a character created by a relative, especially one as iconic as Sherlock Holmes,” said Jennifer Utley, a family historian at Ancestry.

Sherlock first aired in 2010 and returns for its fourth series on Sunday on both US and British television.

Conan Doyle published the first of about 60 Sherlock Holmes stories in 1887. The eccentric, violin-playing character has since become one of the best-known fictional detectives in the world and the inspiration for hundreds of movies, stage plays, books and TV shows.

Ancestry said its researchers looked at everything from church records, censuses, land deeds, newspaper announcements and tombstones to establish the link between Cumberbatch and Conan Doyle.