Treaty of Tordesillas in AP World History: Modern

From Columbus's return in 1493 to a line at 370 leagues

When Columbus sailed back to Iberia in 1493 after his Spanish-funded voyage, Portugal and Spain both had reasons to claim what he'd found. Portugal had spent decades pushing down the African coast and didn't want a rival cutting into its route toward Asia.

Spain turned to Pope Alexander VI, who issued a 1493 decree drawing a line 100 leagues west of the Azores and Cape Verde Islands, favoring Spain. Portugal objected and negotiated directly with Spain. In the 1494 treaty, signed at the town of Tordesillas, the two crowns moved the line out to 370 leagues.

That westward shift had a consequence nobody fully planned. When Pedro Álvares Cabral landed in Brazil in 1500, the coast sat east of the line, so Portugal could claim it. That's why Brazil speaks Portuguese while most of Latin America speaks Spanish.

How one line split Spain's empire from Portugal's

In the course, Tordesillas belongs to Unit 4: Transoceanic Interconnections (1450-1750), mainly Topic 4.2 (Causes of Exploration from 1450-1750) and Topic 4.4 (Maritime Empires Established). The bigger argument there is that European states, not lone adventurers, sponsored ocean voyages and built empires because of political, religious, and economic rivalry with each other.

The treaty shows that rivalry on paper. Both crowns were Catholic and wanted papal approval, both wanted trade wealth, and both wanted to avoid a war over claims.

Their different routes were already set before the treaty. Spain had sponsored Columbus's westward voyage, and Portugal had been exploring the African route for decades. Tordesillas formalized how the two divided their overseas claims, and each kept building along its own route:

• Spain kept looking west, funding later Atlantic and Pacific crossings and conquering the Aztec and Inca states, which led to colonial economies built on encomienda, the hacienda, and silver mining.
• Portugal continued along the African route, which Bartolomeu Dias had opened by rounding the Cape of Good Hope in 1488, and later built a trading-post empire in Africa and Asia that tried to control key points in Indian Ocean trade.

Notice what the treaty couldn't do. Portugal's arrival disrupted Indian Ocean commerce somewhat, but Asian merchants such as Gujaratis, Omanis, and Javanese kept trading, which is the continuity Topic 4.4 asks about. A line in Europe didn't hand Portugal control of Asian seas.

The treaty also left the far side of the globe unclear. Spain and Portugal later disputed the Spice Islands (the Moluccas) and settled that with the Treaty of Zaragoza in 1529.

Why England, France, and the Dutch ignored the line

Tordesillas bound only the two kingdoms that signed it. England, France, and the Netherlands never accepted it, and after the Protestant Reformation, England and the Dutch had even less reason to respect a division rooted in papal authority.

These states sponsored their own voyages, which fits Topic 4.2. Some of their expeditions crossed the North Atlantic hunting for alternative routes to Asia, and they also pursued trade and claims well outside the North Atlantic. Over time they took Caribbean islands, North American territory, and Asian trade through chartered companies like the Dutch East India Company (VOC) and the British East India Company.

That gives you a useful contrast. Tordesillas reflects an early model where Catholic monarchies claimed huge areas by agreement and papal approval. The VOC reflects a later model where merchant companies backed by the state won trade through ships, capital, and force.

Writing causation with Tordesillas, plus the mix-ups to avoid

If the treaty shows up in a multiple-choice question, think about how it illustrates competition between European states and state-backed maritime expansion. It also works well in comparisons with later English, French, and Dutch voyages or the VOC, where the point is what changed in how Europeans built empires.

On the Long Essay or Document-Based Question about causes of European exploration or the rise of maritime empires, it works as specific evidence for state sponsorship and rivalry. A strong answer explains effects: the treaty formalized Spain's claims in the Americas and Portugal's in Africa and Asia, and it put Brazil on Portugal's side of the line. Naming it without those effects earns little.

You can also use it as a contrast with English, French, and Dutch efforts to find alternative routes to Asia, including voyages across the North Atlantic. Those powers weren't bound by the treaty and built their empires on different terms.

The common errors:

The pope didn't write the treaty. Alexander VI's 1493 decree came first. Tordesillas was the 1494 deal Spain and Portugal negotiated themselves to move his line west.

Portugal didn't get zero land in the Americas. Brazil fell on its side.

It wasn't a Europe-wide agreement. Other powers ignored it, and the Indigenous peoples, African states, and Asian states inside the claimed zones had no part in it.