Sincere and forceful bio of evangelical Christian William Wilberforce (Gruffudd), a member of the House of Commons, who spent his years in the British Parliament introducing antislavery legislation. Tells the crusader's story with flashbacks, introducing both foes and friends, including former slave trader John Newton (Finney), who wrote the title hymn (rousingly sung by Gruffudd), as part of his atonement. Senegalese singer N'Dour makes his film debut as freed slave and author Oloudah Equiano.