Age of Discovery
Treaty of Tordesillas (1494)

Shortly after Columbus's return from what would later be called the "West Indies", a division of influence became necessary to avoid conflict between the Spanish and Portuguese. On 4 May 1493, two months after Columbus's arrival, the Catholic Monarchs received a bull (Inter caetera) from Pope Alexander VI stating all lands west and south of a pole-to-pole line 100 leagues west and south of the Azores or the Cape Verde Islands should belong to Castile and, later, all mainlands and islands then belonging to India. It did not mention Portugal, which could not claim newly discovered lands east of the line.

King John II of Portugal was displeased with the arrangement, feeling that it gave him far too little land—preventing him from reaching India, his main goal. He then negotiated directly with King Ferdinand and Queen Isabella of Spain to move the line west, and allowing him to claim newly discovered lands east of it. In 1494, the Treaty of Tordesillas divided the world between Portugal and Spain. Portugal gained control over Africa, Asia, and eastern South America (Brazil), encompassing everything outside Europe east of a line drawn 370 leagues west of the Cape Verde islands (already Portuguese). The Spanish (Castile) received everything west of this line, including the islands discovered by Columbus on his first voyage, named in the treaty as Cipangu and Antilia (Cuba and Hispaniola). The dividing line, situated about halfway between Portuguese Cape Verde and Spanish discoveries in the Caribbean, split the known world of Atlantic islands evenly.

In 1500, Pedro Álvares Cabral, initially considering the Brazilian coast as a large island, claimed it for Portugal east of the dividing line. This claim was acknowledged by the Spanish. Cabral, heading towards India, followed a corridor in the Atlantic negotiated by the treaty for favorable winds. While some speculate earlier secret Portuguese discovery of Brazil, there is no credible evidence for this. Similarly, suspicions about Duarte Pacheco Pereira alleged 1498 discovery lack credibility among historians.

Later the Spanish territory would prove to include huge areas of the continental mainland of North and South America, though Portuguese-controlled Brazil would expand across the line, and settlements by other European powers ignored the treaty.
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