The Berlin Conference begins, where European powers negotiate and formalize their claims to African territories. While not directly related to the Treaty of Tordesillas, it reflects the ongoing European practice of dividing non-European lands among themselves, a practice that began with the Treaty of Tordesillas.

Brazil declares its independence from Portugal, marking the end of Portuguese colonial rule. This significant event is a culmination of various factors, including the shifting power dynamics initiated by the Treaty of Tordesillas and subsequent treaties that shaped colonial boundaries.

The Treaty of San Ildefonso is signed between Spain and Portugal, further adjusting the boundaries established by the Treaty of Madrid. This treaty reflects ongoing negotiations and adjustments as both empires continue to expand and consolidate their territories in the Americas.

The Treaty of Madrid is signed, redefining the borders between Spanish and Portuguese territories in South America. This treaty replaces the Treaty of Tordesillas, acknowledging the reality of colonial expansion and settlement beyond the original demarcation line.

The Iberian Union is formed when Philip II of Spain becomes King of Portugal, uniting the two crowns under a single monarch. This union affects the enforcement of the Treaty of Tordesillas, as both Spain and Portugal are now ruled by the same king.

The Treaty of Zaragoza is signed between Spain and Portugal, complementing the Treaty of Tordesillas by defining their respective spheres of influence in Asia. This treaty helps to further clarify the division of the world between these two maritime powers.

Portuguese explorer Pedro Álvares Cabral lands on the coast of Brazil, claiming it for Portugal. This discovery falls within the Portuguese sphere as defined by the Treaty of Tordesillas, leading to the establishment of Portuguese colonies in South America.

The Treaty of Tordesillas is signed by Spain and Portugal, dividing the newly discovered lands outside Europe between them along a meridian 370 leagues west of the Cape Verde islands. This treaty aims to resolve conflicts over newly discovered lands by Columbus and other explorers.

Pope Alexander VI issues the papal bull Inter Caetera, granting Spain the rights to colonize the lands discovered by Columbus. This decree aims to resolve disputes between Spain and Portugal over newly discovered lands, setting the stage for the Treaty of Tordesillas.

Christopher Columbus, under the patronage of Spain, reaches the New World, landing in the Bahamas. This event sets off a wave of exploration and colonization by European powers, leading to territorial disputes over newly discovered lands.