In 1494 two crowns split the planet with a single meridian, 370 leagues west of the Cape Verde Islands. Nobody alive could measure longitude. So the most consequential line ever drawn sat wherever your cartographer said it sat — and stayed there for 256 years.
370
leagues
west of the Cape Verde Islands. That is the entire geography of the Treaty of Tordesillas. The text named no island, fixed no length for a league, and never converted the distance into degrees.
The map · the raya, 1494 and 1529Schematic world map. The solid red meridian is
the Treaty of Tordesillas line at the value computed by the pilots at Badajoz in 1524, ≈46°37′W;
the shaded strip around it is the full spread of documented placements, 48°47′W to 42°25′W.
The dashed meridian is its antimeridian, fixed at Zaragoza in 1529 roughly 17° east of the Moluccas,
≈145°E. Everything between them was Portugal’s; everything outside was Castile’s.
THE TREATY · 1493–1529
Seven weeks of haggling, one meridian
Pope Alexander VI drew the first line in May 1493, 100 leagues west of the Azores or Cape Verde. Portugal objected that it cut too close to its Atlantic sea lanes. The redraw, signed at Tordesillas on 7 June 1494, shoved the line 270 leagues further west.
Read the chartEven the modern conversions disagree. Tordesillas’ 370 leagues are usually rendered c. 2,100 km — about 5.7 km to the league; Zaragoza’s 297½ as c. 1,763 km, about 5.9 km. The unit itself was never agreed.
THE PROBLEM · LONGITUDE
A line nobody could find
Latitude you can read off the noon sun with a quadrant. Longitude needs a clock that keeps time at sea — and that clock was 270 years away. The treaty knew it: it ordered a joint Spanish–Portuguese voyage to go out and mark the meridian. The voyage never sailed.
Read the chartSix serious attempts at the same line, spread across 6°22′ of longitude — roughly 700 km of Brazilian coast (computed: 6.37° × 111.3 km at the equator). Each was argued in good faith. The 1524 junta at Badajoz put Spanish and Portuguese pilots in one room to settle it and they went home disagreeing.
ON THE GROUND · BRAZIL
The line fell across Brazil
The raya cut the continent from roughly Belém, at the mouth of the Amazon, to Laguna in Santa Catarina. Everything west of it was Castile’s, on paper. Portuguese bandeirantes walked across it anyway, for two hundred years.
Read the chartBy longitude, the treaty handed Portugal about 30% of the east–west span Brazil holds today (a calculation from IBGE’s extreme points, not an area figure). In 1750 the Treaty of Madrid abrogated Tordesillas outright and redrew the border around who was actually living there — uti possidetis, ita possideatis.
THE FAR SIDE · ZARAGOZA
A line on a globe has two halves
Tordesillas fixed one meridian and said nothing about its antimeridian, half a world away — which is where the Spice Islands were. After Magellan’s survivors came home claiming the Moluccas for Spain, the two crowns went back to the table.
350,000
gold ducats paid by Spain to drop its Moluccas claim, 1529
17°
east of the Moluccas — where Zaragoza put the far line
1565
Legazpi lands at Cebu, in Portugal’s half, and stays
Read the chartThe 1529 Treaty of Zaragoza put the far line 297½ leagues — 17° — east of the Moluccas, near the Marianas, and Spain sold its claim for 350,000 gold ducats. The Philippines sat squarely in Portugal’s half. Spain colonised them anyway from 1565.
WHAT IT LEFT · TODAY
One meridian, two languages
The line is gone. Its residue is a continent where 203 million people speak Portuguese and every neighbour speaks Spanish.
203,080,756
people in Brazil, speaking Portuguese
IBGE, Census 2022
8,510,418
km² of Brazilian territory
IBGE, 2023
260M+
Portuguese speakers, four continents
CPLP
600M+
Spanish speakers worldwide
Instituto Cervantes, 2024
Read the numbersThe Treaty of Madrid erased the raya in 1750, but by then it had already decided which language would be spoken from the Amazon to the Paraná.
WHAT TO NOTICE ON THE MAP
Three things the drawing makes obvious
The red line is not a line.
It is a band. The shaded strip through Brazil is the full spread of the places serious people put the same meridian between 1495 and the modern atlas.
The dashed line is the same line.
Half a world east, near the Marianas. One cut, two edges — that is what dividing a sphere means.
Look where the raya touches land.
Brazil, and almost nowhere else. In 1494 the two crowns divided a planet neither of them had seen, and the map shows exactly how little of it they knew.
Sources & notes
Treaty of Tordesillas, 7 June 1494Signed at Tordesillas; ratified by Spain 2 Jul 1494 and by Portugal 5 Sep 1494; confirmed by Pope Julius II, 24 Jan 1506. The two original copies are held by the Archivo General de Indias (Seville) and the Arquivo Nacional da Torre do Tombo (Lisbon) and are inscribed on the UNESCO Memory of the World Register (2007).
Inter caetera, papal bull, 4 May 1493Line set 100 leagues west of the Azores or the Cape Verde Islands. Encyclopædia Britannica; UNESCO Memory of the World.
The six computations of the meridianJaime Ferrer, 1495 (42°25′W); Cantino planisphere, 1502 (42°30′W); Fernández de Enciso, 1518 (45°38′W); pilots at the Badajoz junta, 1524 (46°36′W); Portuguese globe, 1524 (47°17′W). Compiled in the standard cartographic literature on the treaty (Harrisse; Nowell; Morison) and summarised in Wikipedia, “Treaty of Tordesillas,” accessed Sep 2026. The 48°47′W end of the strip is Laguna, Santa Catarina — the southern terminus of the raya as conventionally drawn in Brazilian atlases.
Cantino planisphere, 1502The oldest surviving map to show the Tordesillas line, drawn on six sheets of parchment, 220 × 105 cm. Biblioteca Estense Universitaria, Modena.
Treaty of Zaragoza, 22 April 1529Antimeridian set 297½ leagues (17°) east of the Moluccas, near the Marianas; Spain relinquished its Moluccas claim for 350,000 gold ducats, with a retro-vendendo clause. Guampedia; Encyclopaedia of Portuguese Expansion, NOVA FCSH.
Spanish settlement of the Philippines, 1565Legazpi and Urdaneta reached Cebu in February 1565, on islands the Zaragoza line had placed in the Portuguese half. Treaty of Cebu, 1565.
Treaty of Madrid, 13 January 1750Expressly abandoned Inter caetera, Tordesillas and Zaragoza as the legal basis for the division, substituting uti possidetis. Oxford Public International Law, “Erasing the Line.”
Brazil todayPopulation 203,080,756 (IBGE, Censo Demográfico 2022). Territorial area 8,510,417.771 km² (IBGE, DOU no. 59, 27 Mar 2023). Extreme points: Ponta do Seixas, Paraíba, 34°47′30″W; Serra da Contamana, Acre, 73°59′32″W; east–west span 4,319.4 km (IBGE).
SpeakersMore than 600 million Spanish speakers, of whom almost 500 million are native (Instituto Cervantes, El español en el mundo, 2024). More than 260 million Portuguese speakers across the nine CPLP member states (CPLP).
Note — Illustrative / computed, not measured: the ≈700 km width of the placement band (6°22′ × 111.3 km per degree at the equator); the ≈540 km width at Brazil’s latitude; the “about 30%” share of Brazil’s east–west longitude span east of 46°37′W. The map is schematic: coastlines are hand-simplified and not survey-accurate. Every longitude, date, distance and population figure on it is real and sourced above.