The Mission - 1986

This movie is known for two things, the first of which happens very early in the film. The story begins with the dictation of a letter to the Pope. The letter concerns a series of missions in the Amazon basin. The first priest to the area is shown amongst the tribe. They've lashed him to a wooden cross. They carry the cross into the river and let it go. The camera follows it down the river until (spectacularly) it goes over the falls.
The movie deals with the complex world of South America in the 1750's. Brazil was a Portugese territory while the rest of the continent was firmly Spanish. Jesuit missonaries had gone into the jungles to convert the natives. Some attempts were disasterous and resulted in martydom. Others were very successful. Especially the ones that used music. The movie notes that if the Jesuits had had an orchestra, they could've conqured the all of South America.
But not every plan for the natives was benevolent. Slave traders also went into the jungle. The Spanish forbade slavery while under the Portugese it was allowed. Some Spanish plantation owners bought slaves from the Portugese. The question of who controlled which areas became very important. This movie focuses on one such mission and it's attempt to provide a haven for the natives.
The second thing this movie is known for is it's score. Rich swelling strings. One of the finest that I've heard so far from the 80's. A very good movie.