Along with its diverse ecology, Misiones has an epically rich history thanks to its dense Guaraní population and the Jesuits who proselytized among them. In the early 17th century, the Jesuits abandoned their efforts among the Chaco’s nomadic hunter-gatherers for the semisedentary Guaraní, shifting cultivators who were better candidates for missionization. In all, they founded 30 reducciones, populated with perhaps 100,000 Guaraní, in a territory that now comprises parts of Argentina, Brazil, and Paraguay.

Hollywood rarely depicts history with any accuracy, but director Roland Joffe got it mostly right in his 1986 film The Mission, starring Robert De Niro and Jeremy Irons. Joffe portrayed the Jesuit experiment in organizing indigenous peoples and educating them not just as farmers but also as craftspeople and even performing artists. He also deftly explained the political and economic intrigues of the time, as Portuguese malocas (slavers) and other Spanish settlers coveted the Jesuits’ productive yerba mate plantations and labor monopoly.

Eventually, under pressure from these interests, Spanish king Carlos III expelled the Jesuits from the Americas in 1767. After the expulsion, many indigenes fled to the forest, and the missions fell into ruins, their walls pried apart by strangler figs and their Guaraní-carved sandstone statuary toppled.

After the South American states gained independence in the early 19th century, Misiones was the object of contention among various countries in an area where it took time to fix international borders. After the megalomaniacal Paraguayan dictator Francisco Solano López blundered into the hopeless War of the Triple Alliance (1865–1870) against Argentina, Brazil, and Uruguay, his catastrophic loss left Misiones in Argentine hands.

Administratively, Misiones became part of Corrientes Province, but as colonization proceeded from the west, Misiones became a separate territory with Posadas as its capital. The Urquiza railway’s 1912 arrival at Posadas provided a way for farmers to get their products to market.

Yerba mate remained the major product of enormous properties acquired under questionable circumstances. By the early 20th century, the federal government expropriated some properties and turned them over to agricultural colonists from many countries, including Argentina, Brazil, Denmark, France, Germany, Greece, Italy, Paraguay, Spain, Sweden, Switzerland, the Ukraine, the United States, and even Asia and the Middle East.