This Master’s Thesis investigates the 1637-39 Teixeira’s expedition and how it transformed the Amazon region at the beginning of the seventeenth century. It assumes that this expedition was a key historical event to challenge the balance of power in the area. It shows through historical documents how ethno-geographic knowledge was an essential tool in the discursive construction of the Amazon Natives, undermining their cultural landscapes and initiating the process by which geographical knowledge enabled European territorial power. Foucault’s framework to approach and expound on the relationship between knowledge and power is the theoretical system of analysis that helps to understand the meaning embedded in the historical documents under scrutiny. / text