From Wikipedia, the free encyclopedia. David Schofield (born 16 December 1951) is an English actor. He is best known for his role as Ian Mercer in the films Pirates of the Caribbean: Dead Man's Chest (2006) and Pirates of the Caribbean: At World's End (2007). He also appeared in the films An American Werewolf in London (1981), Gladiator (2000), From Hell (2001), Valkyrie (2008), The Wolfman (2010) and Darkest Hour (2017).