Guaraní forces living in the Jesuit reductions defeat bandeirantes loyal to the Portuguese Empire at the Battle of Mbororé in present-day Panambí, Argentina.

The Guarani are a group of culturally-related Indigenous peoples of South America. They are distinguished from the related Tupi by their use of the Guarani language. The traditional range of the Guarani people is in what is now Paraguay between the Paraná River and lower Paraguay River, the Misiones Province of Argentina, southern Brazil once as far east as Rio de Janeiro, and parts of Uruguay and Bolivia.

Reductions were settlements established by Spanish rulers and Roman Catholic missionaries in Spanish America and the Spanish East Indies. In Portuguese-speaking Latin America, such reductions were also called aldeias. The Spanish and Portuguese relocated, forcibly in many cases, indigenous inhabitants of their colonies into urban settlements modeled on those in Spain and Portugal. The Royal Academy of Spain defines reducción (reduction) as "a grouping into settlement of indigenous people for the purpose of evangelization and assimilation." In colonial Mexico, reductions were called "congregations" (congregaciones).

Bandeirantes were settlers in colonial Brazil who participated in expeditions to expand the colony's borders and subjugate indigenous peoples during the early modern period. They played a major role in expanding the colony to the modern-day borders of independent Brazil, beyond the boundaries demarcated by the 1494 Treaty of Tordesillas. Bandeirantes expeditions also involved the capture and subjugation of indigenous peoples.

The Portuguese Empire was a colonial empire that existed between 1415 and 1999. In conjunction with the Spanish Empire, it ushered in the European Age of Discovery. It achieved a global scale, controlling vast portions of the Americas, Africa and various islands in Asia and Oceania. It was one of the most powerful empires of the early modern period, while at its greatest extent in 1820, covering 5.5 million square km, making it among the largest empires in history. Composed of colonies, factories, and later overseas territories, it was the longest-lived colonial empire in history, from the conquest of Ceuta in North Africa in 1415 to the handover of Macau to China in 1999.