Using a minimalist approach to story and dialogue, the film creates a vision of madness and folly, counterpointed by the lush but unforgiving Amazonian jungle. Although loosely based on what is known of the historical figure of Aguirre, Herzog acknowledged years after the film's release that its storyline is a work of fiction. Some of the people and situations may have been inspired by Gaspar de Carvajal's account of an earlier Amazonian expedition, although Carvajal was not on the historical voyage represented in the film.