Spain/ Portugal: CantinoÕs map of 1502 shows the meridian line in the Atlantic that demarcates Spanish territory (west of the line) from Portuguese possessions (east).

Supervised by Spanish-born Pope Alexander VI, the Treaty of Tordesillas in 1494 divided the world in halfÑinto Spanish and Portuguese territories. Following Portuguese navigator Vasco da Gama's success in discovering a sea route around Africa to India in 1498, King Manuel I commissioned Pedro Alvares Cabral to lead a second voyage of 13 ships and 1,500 men to India. Although he intended to stay close to the west coast of Africa, Cabral sailed far off course and accidentally chanced upon the coast of South America. According to the Treaty of Tordesillas of 1494, any land falling within 370 leagues [2.060 km] west of the Cape Verde Islands was to belong to Portugal, whereas any land discovered west of this meridian would be Spanish territory, as decreed by Spanish-born Pope Alexander VI. The coastline of Brazil therefore fell within the Portuguese sphere of influence and was colonized by Manuel I. However, following PortugalÕs discovery of the Spice Islands of the Moluccas in 1512, Spain contested the line of demarcation. The issue was never fully settled, but the Treaty of Zaragoza in 1529 attempted to resolve the matter by setting the ÔantemeridianÕ as 17 degrees to the east of the Moluccas, thus preventing the Spanish from claiming the Spice Islands. (Photo by: Pictures From History/Universal Images Group via Getty Images)