Tupi

When the Portuguese, French, and Dutch penetrated the interior of Brazil they encountered a number of warlike and aggressive tribes called the Tupi. The coastal Tupi lived mainly by agriculture, growing manioc, yams, tobacco, beans, squash, peppers, and other crops in forest clearings. When the soils were depleted, they would move to a new location, clear the trees, and replant. In the sixteenth century they became embroiled in the wars between Europeans fighting in Brazil, mainly the French and Portuguese, who both employed native allies. Many of the Tupi were forced to work on the plantations, but they fared poorly and died. They suffered from epidemics that swept through their villages, and were forcibly taken from their villages to be sold as slaves, often by enemy tribes. European encroachment spread as the trees were cleared, and sugar plantations were established. Devastated by the recurring wars, disease, and slavery, the remaining Tupi withdrew up the Amazon into interior lands the Europeans did not want.

From the game's History encyclopedia, AoE3: DE 100.19.18309.