A modification of the papal Bull of Demarcation issued in 1493 by Pope Alexander VI, the Treaty of Tordesillas (June 7, 1494) divided the recently discovered New World between its two signatories, Spain and Portugal.
Tordesillas is currently the province of Valladolid, Spain. The treaty divided the newly discovered lands from 1492 onwards in what they called "Antilia and Cipango by Christopher Columbus (Cuba and the Hispaniola, now Haiti and the Dominican Republic).
Map of the Treaty of Tordesillas
The division extends 370 leagues west of the Cape Verde Islands, head of the West African coast already conquered by Portugal.
The territories to the East would belong to Portuga,l and the West to the kingdoms of Castile and Aragon (Spain).
That is, the Treaty of Tordesillas divided the Atlantic Ocean by a line from the North Pole to the South Pole, 370 miles west of the Cape Verde Islands, corresponding to the eastern hemisphere to Portugal and the Western Hemisphere to the Crown of Castile Aragon.