How did Portugal and Spain Plan to “Conquer” the World?

When you have numerous expansionist powers on the European continent during the early modern and colonial eras, it can be challenging to maintain a peaceful and cooperative system. With limited land available and many nations eager to claim their share, how were these ambitious countries supposed to divide it all without resorting to conflict? Negotiation was always an option, but it was often easier said than done.

However, two nations, Portugal and Spain, managed to broker a significant deal for the peaceful division of unconquered land. This was not a simple distribution of a few territories; instead, these nations planned to jointly rule the New World.

The origins of Iberian land disputes can be traced back to Christopher Columbus’s expedition to the New World. Columbus had initially sought sponsorship for his voyage from the Portuguese king, John II, but was unsuccessful. Upon returning to Europe after sailing to the West Indies under the Spanish flag, Columbus stopped at the port in Lisbon. When King John met with Columbus and learned of his discoveries, he insisted that these newly found lands should belong to Portugal, not Spain.

King John had a somewhat valid argument, despite having declined to sponsor Columbus’s trip. Back in 1479, the Treaty of Alcáçovas was signed between Portugal and the Monarchs of Castile and Aragon, concluding the War of Castilian Succession. One aspect of this treaty focused on territorial claims throughout the Atlantic Ocean. According to the treaty, aside from the Canary Islands, all territories contested by the Iberian powers would fall under Portuguese control. This included Madeira, the Azores, Guinea, Cape Verde, and the right to conquer the Kingdom of Fez. Furthermore, Portugal was granted hegemony over the entire Atlantic Ocean south of the Canary Islands, allowing them exclusive rights to explore, trade, and conquer in that region.

Given this context, King John’s claim that the territories discovered by Columbus should belong to Portugal was reasonable, as the West Indies were indeed south of the Canary Islands. Nevertheless, the Spanish monarchs, Ferdinand and Isabella, were unwilling to relinquish their claims to the North and South American territories. Both sides were passionate about their claims but wanted to avoid conflict, leading them to seek a resolution.

Pope Alexander VI played a crucial role in this resolution. Being Spanish-born, Ferdinand and Isabella likely believed he would favor their position. When the Papal Bull was issued, it appeared to give preferential treatment to Spain. The solution involved drawing a line across the map from north to south, 100 leagues off the Cape Verde Islands to the west. The Portuguese were to remain east of this line, while the Spanish would occupy the west. However, this arrangement favored Spain, limiting Portuguese access to new lands in the New World and potentially interfering with their other expeditions.

Seeing this bias, King John requested a meeting with the Spanish monarchs instead of accepting the Pope’s decision. At that time, Portugal was militarily stronger, particularly at sea, so Spain agreed to discuss a new solution to prevent conflict. King John made it clear that Portugal sought explicit rights to more land and sea, proposing to move the line 270 leagues westward, allowing Portugal to explore Brazil and have greater freedom around Africa. The Spanish, feeling they still held the upper hand, agreed to these changes, as the new treaty still granted them the majority of the New World.

This agreement became known as the Treaty of Tordesillas, which was sanctioned in 1506 by Pope Julius II. Although neither pope was directly involved in the negotiations, the treaty was sometimes referred to as the “Papal Line of Demarcation.” Even before this point, the Portuguese began navigating their section of South America. A Portuguese explorer, Pedro Álvares Cabral, is said to have unintentionally landed on the coast of Brazil while en route to India. Whether this was truly accidental remains debated among historians.

Despite claiming that they had not previously discovered this land, many scholars find it unlikely. Nonetheless, the Portuguese took full advantage of the newly found territory and began settling both east and west of the divider. Surprisingly, the Spanish did not react to Portugal’s expansion into Brazil, although they became more protective of their interests in Asia, attempting to limit Portuguese expansion there.

Portugal again sought the Papacy for a resolution to this issue. Pope Leo X favored the Portuguese and declared in 1514 that the original line of demarcation was intended only to divide the Atlantic territories, not the rest of the world. Consequently, both Portugal and Spain continued to respect the original treaty, which remained valid even when the Iberian nations were ruled under the same monarch from 1580 to 1640, and it continued to be effective for another century.

It wasn’t until 1750 that the division of the Atlantic region was revised through the Treaty of Madrid, which recognized the outdated nature of the original agreement. This treaty was later updated in 1761 with the Treaty of El Pardo, and in 1777, the First Treaty of San Ildefonso finally resolved the matter long-term.

Throughout these negotiations, the rest of the colonial world observed without intervening. Other prominent nations in the New World did not acknowledge the original Papal Bull or any subsequent treaties. The entire partnership and agreements were made solely between the Iberian nations, without consideration for the rest of the world, aside from a portion of the initial Papal Bull that required both Spain and Portugal to avoid military action against territories already captured by a Christian power.