Portugal and the Plata: The Conflict of Luso-Hispanic Interests in Southern Brazil and the North Bank of the Rio de la Plata, 1493-1807

Long before the discovery of America by Columbus, the Portuguese, guided by Prince Henry the Navigator, had discovered and taken possession of vast tracts of Africa. As was the practice of the time, title was confirmed by Papal bulls of Pope Nicholas V in 1455 and 1456. The Holy See, while serving to authenticate the ownership of the territory, also acted as an international tribunal in settling disputes and in confirming the succession of rulers.