Portuguese Restoration

With the successful revolt in Portugal against Spanish overlordship in 1640, Brazil reverted to Portuguese sovereignty and was made a viceroyalty. Generally peaceful conditions prevailed between the Spanish and Portuguese in South America until 1680. In that year the Portuguese dispatched an expedition southward to the east bank of the estuary of the Río de la Plata and founded a settlement called Colonia. This move led to a protracted period of strife over ownership of the region, which eventually emerged as the republic of Uruguay in 1828.
Brazilian expansion southward had been preceded by penetration of large sections of the interior. Jesuit missionaries had begun to operate in the Amazon Valley early in the 17th century. Before the middle of the century, parties of Paulistas, the name by which residents of São Paulo were known, had reached the upper course of the Paraná River. Because these expeditions were undertaken principally for the purpose of enslaving the Native Americans, the Paulistas encountered vigorous opposition from the Jesuits. Supported by the Crown in their efforts to protect the Native Americans, the Jesuits finally triumphed. Many Paulistas thereupon became prospectors, and a feverish hunt for mineral wealth ensued. In 1693 rich gold deposits were discovered in the region of present-day Minas Gerais. The resultant gold rush brought tens of thousands of Portuguese colonists to Brazil. The economic expansion of the viceroyalty was further stimulated by the discovery of diamonds in 1721 and, later, by the development of the coffee- and sugar-growing industries.
In 1750 the Treaty of Madrid between Spain and Portugal confirmed Brazilian claims to a vast region west of the limits promulgated in the Treaty of Tordesillas (see Demarcation, Line of). The Treaty of Madrid was later annulled, but its principles were embodied in the 1777 Treaty of Ildefonso.
The Portuguese foreign minister and premier Marquês de Pombal instituted many reforms in Brazil during the reign of Portugal's King Joseph Emanuel. He freed the Native American slaves, encouraged immigration, reduced taxes, eased the royal monopoly in Brazilian foreign commerce, centralized the governmental apparatus, and transferred the seat of government from Salvador to Rio de Janeiro in 1763. Pombal expelled the Jesuits in 1760, because their influence among the Native Americans and growing economic power were resented by many Brazilians.