Having lost the empire in Asia, Portugal's policy makers turned their attention to Brazil, where they intensified the cultivation of sugar, cotton, and spices. This expansion of agriculture required a great deal of labor, which led to the importation of slaves from Angola and Guinea. Amerindians were saved from this fate by the Jesuits, who protected them from enslavement.

The southern part of Brazil was occupied first, and the north, later, owing to resistance put up by Amerindians allied with French pirates. In 1580 the Portuguese conquered Paraíba, and, later, Sergipe. In 1603 they penetrated to Ceará and, later, to Pará, where they founded the city of Belém. In 1637 Pedro Teixeira launched a daring expedition into the Amazon Basin, following the river to its headwaters near the Pacific coast. During the sixteenth and seventeenth centuries, various expeditions were sent into the interior, especially at the end of the seventeenth century when gold was discovered.

These expeditions were made up of adventurers known as bandeirantes (after the Portuguese word for flag) because they traveled under the flag of their leader, who took with him kin, friends, slaves, and friendly Amerindians. These expeditions, which followed rivers into the interior, lasted years. The most notable bandeirantes were Pais Leme, who traveled for seven years throughout present-day Minas Gerais, and his son-in-law, Manuel Borba Gato, who discovered several sources of gold on the Rio das Velhas. In addition to gold, diamonds were also found in abundance. The discovery of gold and diamonds sparked a gold rush from all over the world to Brazil and from the central zones to the interior, which devastated Brazilian agriculture. The gold and diamonds enriched the Portuguese crown and allowed it to spend lavishly on imported goods and baroque palaces, thus destroying once again the initiatives previously taken for indigenous economic development.

Brazilian gold also encouraged England to update its commercial relations with Portugal. The Methuen Treaty of 1703 allowed the Portuguese a preferential duty on wine exported to England, in return for which Portugal removed restrictions on the importation of English-made goods. The Portuguese market was soon absorbing 10 percent of the English export trade, which represented an increase of 120 percent above the quantity of goods imported to Portugal before the treaty. Portuguese exports to England, mainly wine, rose by less than 40 percent. Gold from Brazil was used to pay for this trade imbalance.

Data as of January 1993