With the ratings-busting Christmas special still provoking much debate, the fourth series of Sherlock, with Benedict Cumberbatch in the title role, is gearing up for a spring shoot in London and Wales.

The exact date for the start of principal photography can be found on Production Intelligence (listed on our site from 13 January), along with the names of crucial hires including the casting director, line producer, production designer and location managers.

The latest episode, a gothic and lavish one-off special entitled The Abominable Bride, was shown on New Year”s Day, complete with intricate dream sequences and stories within stories. It attracted 8.4 million viewers, making it the highest-rated TV drama of the festive period, with fellow behemoth Downton Abbey clocking up an average of 6.6 million viewers.

Sherlock has been a huge hit for Hartswood Films, the BBC and co-producer WGBH Boston since its inception in the form of a single pilot in 2009, which was swiftly followed by three 90-minute episodes.

The series has gone on to garner multiple gongs, including BAFTAs and Primetime Emmys. Its popularity even caused a spike in requests for coats similar to that worn by Benedict Cumberbatch in the show, with designers leaping to meet the demand.

PI subscribers can follow the show on our site to receive updates with more key production names as they board Series 4; non-subscribers can click here to request a free demo.