An outstanding achievement.
Herzog tells the tale of a man who declares himself a god, and the trouble that befalls him and his followers. However, he does not act that much different than the Christian God he is spreading the word of. It seems both have evil committed in their name, thoughtlessly and brutally. Even the Monk who narrates, tells the story of God to the "savages" and Aguirre to us savages. And as Aguirre stands over his Kingdom at the end, you are left wondering if God too, will be in much the same boat at the end of mankind. Sadly, there will probably no monkeys for Him to lord over.
This is a beautifully shot, incredibly acted (especially by that madman, Kinski) film with a constant sense of danger from the river the precarious raft is floating on, and the jungle surrounding it. One of the many "must sees" from Herzog's incredible filmography.