David John Bradley is an English actor. He is known for playing Argus Filch in the Harry Potter film series, Walder Frey in the HBO fantasy series Game of Thrones, and Abraham Setrakian in the FX horror series The Strain. He is also an established stage actor, with a career that includes a Laurence Olivier Award for his role in a production of King Lear. Other acting credits include the BBC Two series Our Friends in the North, the ITV series Broadchurch (for which he won the Best Supporting Actor award at the 2014 British Academy Television Awards), the BBC One miniseries Les Misérables, the comedy series After Life and the films Hot Fuzz, The World's End and Captain America: The First Avenger. In 2012, Bradley played Solomon in the Doctor Who episode "Dinosaurs on a Spaceship". In 2013, Bradley portrayed William Hartnell, the actor who played the First Doctor, in the Doctor Who docudrama An Adventure in Space and Time. He returned to Doctor Who in 2017, appearing as the First Doctor in "The Doctor Falls" and "Twice Upon a Time". Since January 2018, Bradley has reprised the role in a series of audio stories released by Big Finish entitled The First Doctor Adventures.