 | Steve Reeves als Glaucus Leto |
 | Christine Kaufmann als Elena / Ione |
 | Fernando Rey als Arbaces, High Priest of Isis |
 | Barbara Carroll als Nydia |
 | Anne-Marie Baumann als Julia |
 | Mimmo Palmara als Gallinus, a Praetorian Guard |
 | Guillermo Marín als Ascanius, Consul of Pompei |
 | Carlo Tamberlani als Olinto, Christian Leader |
 | Mino Doro als Consul |
 | María Silva als Julia's Maid |
 | Jesús Puente als Roman Senator |
 | Vicky Lagos als Woman in Red |
 | Ignazio Dolce als Caius |
 | Mario Berriatúa als Praetorian Guard |
| Mino Doro als Roman Consul |
 | Ángel Aranda als Antoninus Marcus |
| Mario Morales als Marcus, Military Tribune |
| Ángel Ortiz als Helios, a Praetorian Guard |
| Lola Torres als Tavern Keeper |
| Tony Richards |
 | Antonio Casas |
| Ignaz Cole |
| Pedro Fenollar als Announcer |
| Hank Bergman als Roman Soldier (uncredited) |
| Mario Bonnard | Director |
| Lucio Fulci | Associate Producer |
| Sergio Leone | Writer |
| Ennio De Concini | Writer |
| Luigi Emmanuele | Writer |
| Sergio Corbucci | Writer |
| Duccio Tessari | Writer |
| Sergio Corbucci | Assistant Director |
| Sergio Leone | Assistant Director |
| Duccio Tessari | First Assistant Director |
| Eraldo Da Roma | Editor |
| Edward George Bulwer-Lytton | Novel |
| Angelo Francesco Lavagnino | Original Music Composer |
| Julio Peña | Editor |
| Aldo Tommasini | Production Design |
| Vittorio Rossi | Costume Design |
| Ramiro Gómez | Production Design |
| Ramiro Gómez | Set Decoration |
| Antonio L. Ballesteros | Director of Photography |
| Duilio Cambellotti | Costume Design |
| Eduardo Noé | Camera Operator |
| Dario Di Palma | Assistant Camera |
| Domenico Mancori | Camera Operator |
| Alfonso Fabrizio | Production Secretary |
| Giovanni Porcelli | Sound Engineer |
| Renato Silvestri | Supervising Producer |
| Primiano Muratori | Boom Operator |
| Sandro Mancori | Assistant Camera |
| Marcella Benvenuti | Assistant Editor |
| Paolo Moffa | Executive Producer |
| Cesare Seccia | Production Manager |
| Giuseppe Ranieri | Assistant Production Design |
| José Castanyer | Script Supervisor |
| Rafael Ferri | Assistant Production Design |
| Eduardo de la Fuente | Production Manager |
| Renato Silvestri | Production Manager |
| Emilio Ruiz del Río | Matte Painter |
| Enzo Barboni | Second Unit Director of Photography |
| Luigi Pinini | Production Assistant |
| Antonia López | Hairstylist |
| Carmen Martínez | Makeup Artist |
| Dino Galiano | Special Effects |
| Francisco Rodríguez Asensio | Construction Coordinator |
| Antonio Macasoli | Special Effects |
| Adolfo Guerrieri | Still Photographer |
| Irma Tonnini | Wardrobe Supervisor |
| María Luisa Pino | Assistant Editor |
| Rafael Pérez Murcia | Assistant Production Design |
| Augusto Lega | Construction Coordinator |
| Mario Amari | Sound Engineer |
| Eros Bacciucchi | Pyrotechnician |
| Luciana Bagni | Assistant Costume Designer |
| Miguel Asensio Llamas | Production Assistant |
| Antonio Montoya | Production Assistant |
| Angelo Malantrucco | Makeup Artist |
| Augusto Fenollar | Second Assistant Director |
| Sergio Leone | Second Unit Director |
| Sergio Leone | Co-Director |
