The most famed and well-regarded collaboration between New German Cinema director Werner Herzog and his frequent leading man, Klaus Kinski, this epic historical drama was legendary for the arduousness of its on-location filming and the convincing zealous obsession employed by Kinski in playing the title role. Exhausted and near to admitting failure in its quest for riches, the 1650-51 expedition of Spanish conquistador Gonzalo Pizarro (Alejandro Repulles) bogs down in the impenetrable jungles of Peru. As a last-ditch effort to locate treasure, Pizarro orders a party to scout ahead for signs of El Dorado, the fabled seven cities of gold. In command are a trio of nobles, Pedro de Ursua (Ruy Guerra), Fernando de Guzman (Peter Berling), and Lope de Aguirre (Kinski). Traveling by river raft, the explorers are besieged by hostile natives, disease, starvation and treacherous waters. Crazed with greed and mad with power, Aguirre takes over the enterprise, slaughtering any that oppose him. Nature and Aguirre's own unquenchable thirst for glory ultimately render him insane, in charge of nothing but a raft of corpses and chattering monkeys. Aguirre, der Zorn Gottes (1973) was based on the real-life journals of a priest, Brother Gaspar de Carvajal (played in the film by Del Negro), who accompanied Pizarro on his ill-fated mission.
~ Karl Williams, All Movie Guide