Final answer:
The Treaty of Tordesillas, signed in 1494, was an agreement between Spain and Portugal to divide the non-Christian world outside Europe. Spain gained lands to the west of a designated meridian line, while Portugal received territories to the east.
Step-by-step explanation:
The two countries that were signatories to the Treaty of Tordesillas in 1494 were Spain and Portugal. This historic agreement was engineered to resolve disputes over newly discovered lands outside Europe by allotting them between the Spanish and Portuguese empires. According to the treaty, the non-Christian lands to the west of a line one hundred leagues west of the Cape Verde Islands were designated for Spain, whereas those to the east were allocated to Portugal. This division was later represented in a Spanish map from 1622, showing the vertical line through the Atlantic Ocean and granting Portugal rights over the eastern part of modern-day Brazil and other territories, leaving the rest of the Americas for Spain.
As a consequence, when explorers like Pedro Álvares Cabral and Vasco da Gama later navigated to the regions of South America and India respectively, their discoveries were claimed under the provisions of this agreement. This set precedence for the era of colonization by these European powers, affecting global trade and geopolitical dynamics for centuries to come.