France, 17th century, during the reign of Louis XIII. When a dear friend, the Duke of Nevers, is treacherously assassinated by a powerful relative, a skilled swordsman, the noble Henri de Lagardère, seeks his rightful vengeance as he tries to protect the innocent life of the duke's last heir.
Unfortunately the movie On Guard is not yet available on HBO Max.
| Directing | Philippe de Broca | Director |
| Production | Gianluca Lazzaroni | Production Secretary |
| Crew | Ian Burley | Translator |
| Camera | Alain Dutartre | First Assistant Camera |
| Production | Nora Salhi | Production Accountant |
| Crew | Corinne Devaux | Choreographer |
| Sound | Valérie Lindon | Music Producer |
| Crew | Christophe Maratier | Armorer |
| Costume & Make-Up | Tess Hammami | Costumer |
| Production | Catherine Deserbais | Extras Casting |
| Camera | Jean-Marie Leroy | Still Photographer |
| Camera | Philippe Canu | Grip |
| Sound | London Symphony Orchestra | Music |
| Art | Caroline Ruelle | Location Scout |
| Crew | Guy Di Rigo | Stunts |
| Camera | Yves Agostini | Camera Operator |
| Crew | Alain Saugout | Stunts |
| Crew | Patrice Cossonneau | Stunts |
| Costume & Make-Up | Brigitte Bourneuf | Costumer |
| Art | Emmanuel Rondeau du Noyer | Location Scout |
| Art | Patrick Boshart | Location Scout |
| Crew | Guillaume Castillon | Stunts |
| Lighting | Richard Vidal | Electrician |
| Crew | Josy Venon | Stunts |
| Crew | Patrick Médioni | Stunts |
| Crew | Philippe Morel | Stunts |
| Crew | Pascal Madura | Stunts |
| Editing | Pauline Casalis | Assistant Editor |
| Camera | Jean-Paul Agostini | Second Assistant Camera |
| Crew | Philippe Guégan | Stunts |
| Costume & Make-Up | Florence Sadaune | Assistant Costume Designer |
| Crew | Lionel Vitrant | Stunts |
| Crew | Pascal Guégan | Stunts |
| Crew | Christian Hening | Stunts |
| Crew | Barbara Dupont | Stunts |
| Crew | Vincent Sentis | Carpenter |
| Directing | Vincent Dachet | Third Assistant Director |
| Visual Effects | Fred Place | Digital Compositor |
| Production | Olivier Lagny | Assistant Production Manager |
| Production | Yann Arnaud | Assistant Unit Manager |
| Costume & Make-Up | Nathalie Tabareau | Makeup Artist |
| Crew | Daniel Breton | Stunts |
| Art | Marc Renault | Property Master |
| Crew | Bertrand Terreyre | Carpenter |
| Directing | Delphine Bouix | Third Assistant Director |
| Costume & Make-Up | Stephanie Orillard | Makeup Artist |
| Crew | Jean-Claude Braquet | Stunts |
| Production | Didier Abot | Assistant Unit Manager |
| Production | Françoise Galfré | Executive Producer |
| Costume & Make-Up | Michel Deruelle | Makeup Artist |
| Crew | Alain Barbier | Stunts |
| Sound | Laurent Quaglio | Sound Supervisor |
| Production | Michel Jullien | Unit Production Manager |
| Production | Vittorio Cecchi Gori | Co-Producer |
| Crew | Christian Bergner | Stunts |
| Visual Effects | Paul Swendsen | Matte Painter |
| Costume & Make-Up | Michèle Constantinides | Makeup Artist |
| Crew | William Cagnard | Stunts |
| Crew | Michel Anderson | Stunts |
| Visual Effects | Frédéric Moreau | Visual Effects |
| Art | Stéphane Cressend | Property Master |
| Art | Ivan Casidanus | Assistant Property Master |
| Visual Effects | Isabelle Roussel | Digital Compositor |
| Directing | Serge Onteniente | Assistant Director |
| Visual Effects | Christian Rajaud | Digital Effects Producer |
| Sound | William Flageollet | Sound Re-Recording Mixer |
| Art | Jiri Hanibal Jr. | Sculptor |
| Costume & Make-Up | Benoît Lestang | Makeup Artist |
| Production | Rita Rusić | Co-Producer |
| Crew | Jean-Louis Airola | Stunts |
| Visual Effects | Christian Guillon | Special Effects Supervisor |
| Art | Sylvie Deldon | Assistant Decorator |
| Crew | Henri Lorente | Carpenter |
| Directing | Olivier Coutard | Second Assistant Director |
| Camera | Jean-François Robin | Director of Photography |
| Editing | Henri Lanoë | Editor |
| Sound | Philippe Sarde | Original Music Composer |
| Writing | Jérôme Tonnerre | Writer |
| Art | Bernard Vézat | Production Design |
| Sound | Henri Morelle | Sound |
| Production | Patrick Godeau | Producer |
| Writing | Jean Cosmos | Screenplay |
| Writing | Philippe de Broca | Screenplay |
| Writing | Paul Féval | Novel |
