 | José Sacristán als Miguel de Unamuno (voice) |
 | Marian Álvarez als Researcher (voice) |
 | Víctor Clavijo als General Millán-Astray (voice) |
 | Andrés Gertrúdix als Bartolomé Aragón (voice) |
 | Antonio de la Torre als General Mola (voice) |
 | Miguel Cubero als José María Pemán (voice) |
| Ramón Mayrata als Father Tusquets / Gen. Gonzalo de Aguilera (voice) |
 | Vicente León als Manuel Azaña / Francisco Maldonado (voice) |
| Javier Maqua als Francisco Bravo (voice) |
| Margarita Arnaz als Susana Unamuno (voice) |
| Helvia Álvarez als Researcher |
| Miguel de Unamuno Adarraga als Self - Grandson |
 | Miguel de Unamuno als Self - Writer (archive footage) |
 | King Alfonso XIII of Spain als Self (archive footage) |
| Indalecio Prieto als Self - Politician (archive footage) |
| Francisco Largo Caballero als Self - Politician (archive footage) |
| Pedro Rico López als Self - Politician (archive footage) |
| Niceto Alcalá-Zamora als Self - Politician (archive footage) |
| Manuel Azaña als Self - Politician (archive footage) |
| José María Gil-Robles als Self - Politician (archive footage) |
 | Adolf Hitler als Self - Politician (archive footage) |
 | Benito Mussolini als Self - Politician (archive footage) |
| José Millán-Astray als Self - Military (archive footage) |
 | Francisco Franco als Self - Politician (archive footage) |
| Manuel Menchón | Director |
| Manuel Menchón | Writer |
| Iván Palomares | Original Music Composer |
| Ana Muñoz de Terry | Art Direction |
| Marga Barcoj | Production Director |
| José Tomé | Sound Designer |
| Alexey Krivosheev | Visual Effects Supervisor |
| Renato Sanjuán | Editor |
| Javier Calvo | Director of Photography |
| Mario Madueño | Executive Producer |
| Manuel Menchón | Producer |
| Mario Madueño | Producer |
| Manuel Menchón | Executive Producer |
| Andrés Luque | Executive Producer |
| Itziar Sagasti | Art Direction |
| Pablo Ontoria | Assistant Director |
| Helvia Álvarez | Researcher |
| Araceli Uzquiano | Archival Footage Research |
| Iker Criado | Gaffer |
| Jon Azcorra | Grip |
| Carmen de Couto | Assistant Editor |
| Diego Polo | Special Effects |
| José Tomé | Sound Supervisor |
| Juan Egoscozabal | Foley Artist |
| Carlos Pérez Valero | Foley Artist |
| Jorge Marín | Sound Mixer |
| Javier Camarasa | Sound Recordist |
| Martín Grignaschi | Sound Recordist |
| Pedro Lozano | Post Production Supervisor |
| Paola Botrán | Post Production Supervisor |
| Cristina Ruiz | Colorist |
| Cristina Ruiz | Graphic Designer |
