Sherlock Holmes has been a box-office success with Robert Downey Jr.s take on the legendary Detective, but now the character is returning to the small screen.

BBC Worldwide and PBS' Masterpiece Theatre are coming together to co-produce a new television series based on the Sherlock Holmes novels. Unlike the current big-screen adaptation though, this series will be a modern day saga with some classic stories. Benedict Cumberbatch has been cast as Holmes with UK star Martin Freeman stepping into the shoes of Watson.

The series has been created by current Doctor Who showrunner, Steve Moffat, along with Doctor Who writer, Mark Gatiss.

Everything that matters about Holmes and Watson is the same, Moffat said in the press release. Conan Doyle's stories were never about frock coats and gas light; they're about brilliant detection, dreadful villains and blood-curdling crimes - and frankly, to hell with the crinoline. Other detectives have cases, Sherlock Holmes has adventures, and that's what matters. Mark and I have been talking about this project for years, on long train rides to Cardiff for Doctor Who. Quite honestly, we'd still be talking about it if Sue Vertue of Hartswood Films (conveniently also my wife) hadn't sat us down for lunch and got us to work.

For those worried that the contemporary setting will loose some of the Holmes charm, Piers Wenger, the Head of Drama at BBC Wales, explained that he will still have the same atmosphere as the original stories but now he will be a real life superhero.

Our Sherlock is a dynamic superhero in a modern world, an arrogant, genius sleuth driven by a desire to prove himself cleverer than the perpetrator and the police, everyone in fact, he said.

Also being developed as part of the duumvirate is Upstairs Downstairs, a series that previously aired in the 1970s. The original charted the period between 1903 and 1930 and lead up to the outbreak of the World War II. This new adaptation will continue six years after where the original concluded and will be set in 1936.

Unlike Holmes, this drama will air as two 90-minute movies and Jean Marsh has signed on to reprise the role of Rose.

Masterpiece is also developing Aurelio Zen, which will be filmed in Italy. This will run over three episodes and will be an adaptation of the Michael Dibden novel.

"I'm so proud of this particular group of programs," executive producer Rebecca Eaton said. "These three series say everything about what 'Masterpiece' aims to be: iconic, rich with wonderful actors, witty, literate and timeless. I can't wait to see them all."