Joseph Fiennes & Natascha McElhone Board Guy Ritchie’s ‘Young Sherlock’ Series

Guy Ritchie’s Young Sherlock series has cast the boy genius’s parents.

Sherlock’s dad Silas will be played by Joseph Fiennes, while Natascha McElhone is Sherlock’s mum Cordelia. Fiennes, who we revealed earlier today is starring in the BBC’s drama about Nazanin Zaghari-Ratcliffe, joins his real-life nephew Hero Fiennes Tiffin, who is playing the protagonist.

More from Deadline

Sherlock’s father is a scientist, explorer and self-made businessman, while his mum is described as a devoted mother, artist and matriarch of the Holmes clan.

Inspired by Andy Lane’s critically acclaimed book series, Prime Video’s show follows the 19-year-old, disgraced, raw, unfiltered, and unformed genius, when he finds himself caught up in a murder mystery at Oxford University that threatens his freedom. Diving into his first-ever case with a wild lack of discipline, Sherlock manages to unravel a globe-trotting conspiracy that will change his life forever. Ritchie is set to direct and executive produce the eight-episode series, which will premiere exclusively on Prime Video in more than 240 countries and territories worldwide.

Along with the Zaghari-Ratcliffe project, Fiennes is also leading Dear England, the BBC’s TV version of the stage play about the England soccer team in which he plays manager Gareth Southgate. McElhone recently starred as Dr. Catherine Halsey in the Paramount+ series Halo and as Bella Ainsworth in Hotel Portofino.

Matthew Parkhill is writer, showrunner and executive producer. Simon Kelton (Eddie the Eagle), Ivan Atkinson (The Gentlemen), Simon Maxwell (The Woman in the Wall, Deep State), Dhana Gilbert (The Marvelous Mrs. Maisel), Colin Wilson (The Mandalorian), Marc Resteghini also executive produce. Harriet Creelman serves as co-executive producer. Kelton originally conceived the project and packaged it with Atkinson, then partnered with Motive Pictures, Gilbert, and Resteghini, who developed and brought the series to Amazon MGM Studios. Gilbert and Resteghini have overall deals with Amazon MGM Studios.

Fiennes is represented by The Artists Partnership and WME. McElhone is represented by CAA and Independent Talent Group.

Best of Deadline

Sign up for Deadline's Newsletter. For the latest news, follow us on Facebook, Twitter, and Instagram.