Treaty of Madrid in 1750 determined how Spain and Portugal would divide the South American continent between them, the Spanish king promised to evacuate all the settlements that were founded on the territory recognized as Portuguese. Among other things, this promise implied the obligation to evacuate seven Jesuit missions with some 30,000 Guaranis. The treaty made special arrangements for this evacuation, specifying that the missionaries would abandon the missions with their residents (the Guaranis), who would thereafter be resettled elsewhere within the territories recognized as Spanish. While residents and Jesuits could take with them all moveable goods, the houses, buildings, churches and lands would remain intact and would be transferred to Portugal.

The Jesuit missions were safe, because they were protected under Spanish law. The Treaty of Madrid (in the year 1750) reapportions the land in South America. The land on which the Jesuit missions were located was transferred to the Portuguese, and Portuguese law allows slavery. The Portuguese colonials seek to enslave the natives, and as the independent Jesuit missions might impede this, Papal emissary Cardinal Altamirano (Ray McAnally), a former Jesuit priest himself, is sent from the Vatican to survey the missions and decide which, if any, should be allowed to remain.

In 1750 Spain and Portugal signed a treaty renegotiating a borderline between Spanish and Portuguese territories in South America, with Portugal taking control of a previously Spanish region on the Paraguay River. In this region were a number of mission communities, founded
by the Society of Jesus, where thousands of native Guaraní converts lived. These missions (called "reducciones" or "reductions") were not simply spiritual centers, but thriving economic communities where converts worked together and prospered.
The Jesuit missionaries, who were ardent champions of the Pope, strongly opposed slavery, an institution long condemned by Rome.
Once the Spanish withdrew, the only protection remaining to the Guaraní would be the Jesuit reducciones. The Portuguese, of course, wished to see the missionaries depart from the region together with the Spanish civil authority.

On the occasion of the 100th anniversary of cinema in 1995, the Vatican compiled this list of "great films." The 45 movies are divided into three categories: "Religion," "Values" and "Art." The Mission is one of the 15 films listed in the category "Religion" on the Vatican film list.

It won the top prize at Cannes in 1986 and was nominated for a Best Film Oscar; but for many American critics and audiences, Roland Joffé’s The Mission was something of an enigma.

"'The Mission,'' which was awarded the grand prize at this year's Cannes Film Festival, is a singularly lumpy sort of movie. The film's most riveting sequence comes at the very beginning, when we see a crucified Jesuit missionary being tossed - cross and all - into the river and carried over the spectacular Iguassu Falls. Nothing that follows, including more pretty scenery and quaint costumes, comes close to equaling the drama of that one sequence - about a character who remains forever anonymous.

Guaraní, South American Indian group living mainly in Paraguay and speaking a Tupian language also called Guaraní. Smaller groups live in Argentina, Bolivia, and Brazil. Modern Paraguay still claims a strong Guaraní heritage, and more Paraguayans speak and understand Guaraní than Spanish. Most of the people who live along the Paraguay River around Asunción speak Guaraní, which, with Spanish, is an official language of Paraguay. At the turn of the 21st century, the Guaraní in South America numbered nearly five million.

The Guaraní were the original residents of a region that now comprises Paraguay, Uruguay, northern Argentina and southern Brazil; today in Paraguay alone, 95 percent of Paraguayans are of Guaraní ancestry. In the 16th Century, the Spanish arrived looking for riches and conquest; soon after, Catholic missionaries followed, looking for converts. But when slave traders began to kidnap and kill the Guaraní, terrorizing and massacring mission towns, the Jesuits decided to fight back. By training and arming the Guaraní, this Indigenous-Jesuit alliance became one of the fiercest fighting forces in the Americas. The 1986 movie "The Mission," starring Robert de Niro, is based on this story.

Jesuit, member of the Society of Jesus (S.J.), a Roman Catholic order of religious men founded by St. Ignatius of Loyola, noted for its educational, missionary, and charitable works, once regarded by many as the principal agent of the Counter-Reformation, and later a leading force in modernizing the church.

Spain led European global exploration and colonial expansion in the fifteenth and sixteenth centuries. Trade flourished across the Atlantic and Pacific Oceans. Toppling the Aztec and Inca civilizations, Spain laid claim to vast territories in North and South America.

During the fifteenth and sixteenth centuries, with its global empire which included possessions in Africa, Asia and South America, Portugal was one of the world's major economic, political, and cultural powers.