Michael Apted Director Ioan Gruffudd William Wilberforce Actor Romola Garai Barbara Spooner Actor Benedict Cumberbatch William Pitt Actor Albert Finney John Newton Actor Michael Gambon Lord Charles Fox Actor Rufus Sewell Thomas Clarkson Actor Youssou N'Dour Olaudah Equiano Actor Ciarán Hinds Lord Tarleton Actor Toby Jones Duke of Clarence Actor Nicholas Farrell Henry Thornton Actor Sylvestra Le Touzel Marianne Thornton Actor Jeremy Swift Richard the Butler Actor Stephen Campbell Moore James Stephen Actor Bill Paterson Lord Dundas Actor Nicholas Day Sir William Dolben Actor Georgie Glen Hannah Moore Actor Steven Knight Writer Edward R. Pressman Producer Terrence Malick Producer Patricia Heaton Producer David Hunt Producer Ken Wales Producer Jeanney Kim Executive Producer James Clayton Executive Producer Duncan Reid Executive Producer Remi Adefarasin Cinematographer Rick Shaine Film Editing David Arnold Original Music Charles Wood Production Design Jenny Beavan Costume Design Nina Gold Casting David Allday Art Director Eliza Solesbury Set Decoration