Spanish & Portuguese Empires

In June 1494, diplomats from Spain and Portugal sat across from each other in the small Castilian town of Tordesillas and agreed to divide the world in half. Neither delegation had visited most of the lands they were partitioning. Neither consulted the people who lived there. Pope Alexander VI had already sketched a preliminary boundary the year before; now the two Iberian crowns refined it, shifting the line westward to 370 leagues past the Cape Verde Islands. Everything to the east belonged to Portugal. Everything to the west belonged to Spain.

Brazil, which no European had yet landed on, fell just inside Portugal's half. The rest of the Americas went to Spain. Africa and Asia were Portugal's domain. Two kingdoms with a combined population smaller than the Aztec Empire had, with a stroke of ink, claimed jurisdiction over most of the planet.

The treaty was absurd. It was also enforceable, at least against other European powers, because Spain and Portugal had something no one else yet possessed: deep-water naval capability, firearms mounted on ocean-going ships, and a willingness to use both without hesitation.