James Metcalfe "Jamie" Campbell Bower (born 22 November 1988) is an English actor, singer and model. Bower is best known for his roles as Anthony Hope in Tim Burton's Sweeney Todd: The Demon Barber of Fleet Street, Caius in The Twilight Saga, King Arthur in the Starz original series Camelot and as the young Gellert Grindelwald in Harry Potter and the Deathly Hallows – Part 1. In 2013, he portrayed Jace Wayland in The Mortal Instruments: City of Bones