July 2: The Treaty of Tordesillas was ratified by Spain in 1494.

Lines dividing the non-Christian world between Castile (modern Spain) and Portugal: the 1494 Tordesillas meridian (purple) and the 1529 Zaragoza antimeridian (green)

On July 2, 1494, Spain ratified the Treaty of Tordesillas, which was signed on June 7 before, by Spain and Portugal, to divide the New World, with the intervention of Pope Alexander VI, as conciliator and head of the Church.

A world map depicting the meridian, 1502. The map is particularly notable for portraying a fragmentary record of the  Brazilian coast, discovered in 1500 by the Portuguese explorer Pedro Alvarez-Cabral, and for depicting the African coast of the Atlantic and Indian Oceans with a remarkable accuracy and detail, by Alberto Cantino.

The signatories were representatives of the Catholic Church, monarchs Ferdinand of Aragon and Isabella of Castile, by Spain; and João II of Portugal. The planet was divided into two hemispheres by an imaginary line 370 leagues west of the Cape Verde Islands, off the coast of Senegal, Africa.

West and the recently reached Americas, Tordesillas line depicted - Cantino planisphere detail

(The League was a measure of length referring to the distance a walker could walk in an hour, and that in the twentieth century became five kilometers, ie, 370 * 5 = 1850 kilometers to the west of the Cape Verde Islands).

The rhumb-line construction scheme and geographic lines in the Cantino planisphere or world map. Adapted from Gaspar (2012)

The land to the west of this meridian belonged to the Spanish crown, and the eastern to the Portuguese. As the eastern outgoing territory of South America was within the Portuguese area, this country begun the colonization of Brazil in 1500.

Catholic priests believed they had a divine right to guide, not just to their Christian sheep but also the infidels and savages, by the grace of God.

This map shows the division between Spain and Portugal lands in the newly discovered Americas, in Africa, and in the East. The Papal dividing line was set up by Pope Alexander VI in 1493 at the request of Spain’s rulers to protect their claims from the Portuguese. The following year Spain and Portugal agreed in the Treaty of Tordesillas to move the dividing line about 800 miles west. This treaty would give South America a bilingual European heritage. Today Portuguese is the language of Brazil, while Spanish is spoken in most of the rest of the continent.