Emperor is a 2020 American Western historical drama film directed by Mark Amin (in his directorial debut) and written by Amin and Pat Charles. The film stars Dayo Okeniyi, James Cromwell, Kat Graham, and Bruce Dern. It is based on the true story of Shields Green, an African American slave nicknamed "Emperor", who escaped to freedom and participated in abolitionist John Brown's raid on Harpers Ferry.