Jesuit Reductions
In a long history of conflicts between the empires of Portugal and Spain in America, the Portuguese made numerous incursions – some of them permanent – into Spanish-claimed territory. Slave raids by Bandeirantes (frontiersmen from what is now Brazil) into the Jesuit Reductions of Paraguay carried off many Guaraní inhabitants, who feared and despised the Brazilians. The boundaries between the two empires were not resolved and the conflicts continued after independence, when Portuguese America became the Empire of Brazil. Brazil had no practical access to its own territory of Mato Grosso except by sailing from the Atlantic Ocean up the River Paraguay (see map); fear that Paraguay might interfere with the navigation was a source of conflict. Where Paraguay ended, and where the Mato Grosso began, was a matter of opinion.