Revising a papal bull of 1493, the treaty drew an imaginary line roughly 370 leagues west of the Cape Verde islands, granting Spain lands to the west and Portugal everything east — including, unknowingly, most of Brazil. The agreement shaped the linguistic and colonial map of the Americas for centuries, though it completely ignored the peoples already living there.
Columbus's return from his first voyage in 1493 set off a scramble between Europe's two great seafaring powers. Pope Alexander VI's bull Inter caetera drew a line 100 leagues west of the Azores and Cape Verde islands and gave Castile the lands beyond it, but King John II of Portugal objected that the line cramped his Atlantic routes.
Direct talks at Tordesillas, in Castile, moved the meridian to 370 leagues west of the Cape Verde islands, and the treaty was signed on June 7, 1494. Spain ratified it on July 2 and Portugal on September 5; papal confirmation did not come until Pope Julius II endorsed it in 1506.
The shift proved momentous. When Pedro Álvares Cabral reached Brazil in 1500, its eastern bulge lay on the Portuguese side of the line, which is why Brazilians speak Portuguese today. Neither crown consulted the peoples who already lived in the lands being divided, and rival European powers such as France, England and the Netherlands never accepted the arrangement.
Key people: John II of Portugal, Ferdinand II of Aragon, Isabella I of Castile