the story is based (loosely) in fact: in XVI-century Peru, a Spanish expedition has just crossed the Andes and is making the descent towards the Amazon river. we see them struggle with the jungle, the difficult terrain and the constant rain as they try to make their way, encumbered by their horses, lady-carrying litters, and equipment.
the leader of the expedition decides to send an advance down the Amazon, led by Pedro de Ursia; Aguirre is second-in-command.
once on the river the group is divided into three rafts and begins the journey – there are attacks from hostile indians, internal strife, and a revolt. de Ursia is removed from leadership. food supplies are running out, fever is rampant and arrows continue to fly in from nowhere
here's a bit more of the marvelous opening shot hey, it's the entire movie! I didn't notice that before. entire movie
the Aguirre soundtrack by Popol Vuh contributes to the dreamlike quality of the trip downriver
NOTE: If you want to read about Lope de Aguirre, you can start at the wiki
De Aguirre’s letter to Phillip of Spain http://www.losttrails.com/pages/Tales/deAguirre