AP® World History: Modern · Unit 4 · Topic 4.2
The Voyages and the Line of Tordesillas
In 1494, Spain and Portugal drew a line through the Atlantic and agreed to split any newly found lands between them, a deal made possible by papal authority and by Columbus's 1492 voyage, which only worked because an unexpected continent happened to be in the way.
Portugal spent the 1400s inching down Africa's coast looking for a sea route to Asian spices. Bartolomeu Dias rounded the Cape of Good Hope in 1488, proving the Indian Ocean was reachable by sea, and Vasco da Gama finished the job in 1498, sailing all the way to Calicut, India. Spain, locked out of this African route, backed a different bet: Christopher Columbus's plan to reach Asia by sailing west. Columbus underestimated Earth's circumference badly, by thousands of miles, so when he hit land in October 1492 he assumed it was islands near Asia. It wasn't a rounding error. His ships carried only weeks of food and water, nowhere near enough for the real distance to Asia. Without the Americas sitting unexpectedly in his path, his crews would have starved on open ocean.
Spain's claim to these new lands alarmed Portugal, which already had papal backing for its African and Asian routes. The two Catholic crowns settled the dispute with the Treaty of Tordesillas in 1494, drawing a line 370 leagues west of the Cape Verde Islands. Everything west of the line went to Spain, everything east to Portugal, splitting the entire non-Christian world between two kingdoms that simply assumed they had the right to do it.
The line looked tidy until Pedro Cabral's Portuguese expedition landed on the coast of Brazil in 1500. Brazil fell east of the line, so instead of forcing a renegotiation, it simply dropped into Portugal's existing half, explaining why Brazil speaks Portuguese today while the rest of Spanish America does not. Magellan's expedition later completed the first circumnavigation in 1519-1522, proving just how much ocean and how many claims still lay beyond that single Atlantic line.
Key terms
- Treaty of Tordesillas
- An agreement between Spain and Portugal in 1494 dividing newly claimed lands along a line in the Atlantic Ocean.
- League
- A unit of distance used in the treaty, roughly three miles, used to fix the line 370 leagues from Cape Verde.
- Circumnavigation
- Sailing all the way around the globe, first completed by Magellan's expedition between 1519 and 1522.
- Cape of Good Hope
- The southern tip of Africa that Bartolomeu Dias rounded in 1488, opening a sea route toward Asia.
Watch it explained
- How it worksTrace Dias, da Gama, Columbus and Magellan's crews on one globe with dates ticking.
- Worked exampleShow me the Tordesillas line 370 leagues west of the Cape Verde Islands and what it hands each crown.
- Common mistakeWhy isn't Columbus's mistake about the size of the earth just a rounding error?
- Going furtherWhat changes about the line once Cabral bumps into Brazil in 1500?
Check yourself
End of topic.