Pressburger's novel was loosely based on the last raid of real-life anarchist guerrilla Antonio Sabate who was killed in an ambush in 1959. Based on Emeric Pressburger's novel A Mouse on Sunday, Behold a Pale Horse stars Gregory Peck as a Republican war veteran Manuel Artiguez who continues waging a one-man offensive 20 years after hostilities have officially ceased. By 1964, it was possible for a major studio to make a film touching upon the Spanish Civil War without having to answer to some senate investigating committee or other.