Valentinian is a Jacobean stage play written by John Fletcher, a revenge tragedy based on the life of the Roman emperor Valentinian III (r. 425–455), and originally published in the first Beaumont and Fletcher folio of 1647. The play dramatizes the story of Valentinian, one of the last Roman emperors in the western Roman Empire and last ruler of the conjoined Valentinianic–Theodosian dynasty, as recorded by the Late Antique Greek historian Procopius. His assassin in the play is based on Petronius Maximus (r. 455), Valentinian's short-reigning successor.