He is best known for his roles as Athos in the 2014-2016 BBC series The Musketeers, Dolokhov in the 2016 BBC literary-adaptation miniseries War & Peace, the eponymous character Cormoran Strike in the 2017 BBC series Strike, Orson Welles in the 2020 film Mank, and Praetorian Jack in Furiosa: A Mad Max Saga.
He is the Godson of Alan Rickman.