Treaty of Tordesillas (1494): what it says, what it is worth

The text is dated and placed: at the town of Tordesillas, on the seventh day of June, in the year of the nativity of our Lord Jesus Christ 1494. Three representatives of each side signed it. For Ferdinand and Isabella: Enrique Enríquez, Gutierre de Cárdenas and doctor Rodrigo Maldonado. For John II: Rui de Sousa, his son João de Sousa and Aires de Almada. What they settle fits in a sentence, and here it can be given in the English of Frances Gardiner Davenport, which the Avalon Project publishes: “a boundary or straight line be determined and drawn north and south, from pole to pole, on the said ocean sea, from the Arctic to the Antarctic pole”, at “a distance of three hundred and seventy leagues west of the Cape Verde Islands”. East of it the lands belong forever to the king of Portugal; west of it, to the king and queen of Castile.

The rest of the treaty is a traffic regulation. Neither side sends ships to the other’s side any more, not to discover, not to trade, not to conquer. If a Castilian ship does find land on the Portuguese side, it goes to the king of Portugal and must be handed over at once, and the reverse holds for a Portuguese ship. Castilian ships may cross Portuguese seas to reach their own possessions, provided they hold a direct course and seize nothing before passing the line. One clause even settles the case in hand: whatever Castile may have found before 20 June 1494 within the first 250 leagues goes to Portugal, whatever it may have found in the next 120 leagues stays with it.

The line still has to be drawn for real, and the treaty says how. Within ten months, two to four caravels are to meet at Gran Canaria, each crown putting aboard equal numbers of pilots, astrologers and sailors, and some of each side’s men boarding the other’s ships, so that nobody measures alone. They go to the Cape Verde Islands, then due west. If the line cuts an island or a mainland, at the point of intersection “some kind of mark or tower shall be erected”, then further marks in a row, and the subjects of the two kings may not cross them. The negotiators swear on the Gospel to observe everything, and swear in addition never to ask the pope to release them from it, while asking him to confirm the agreement. Ratifications are to be exchanged within a hundred days, on parchment, with a leaden seal hanging.

Before 1494 the Atlantic was already divided, differently. The peace of Alcáçovas, signed on 4 September 1479, left the Canaries to Castile and recognised Portugal’s monopoly of the African coasts south of the parallel of those islands: that is how the UNESCO nomination file sums up its content. A bull of Sixtus IV, Aeterni regis clementia, of 21 June 1481, confirmed to the king of Portugal jurisdiction over the lands discovered and to be discovered from Cape Bojador as far as India, and confirmed part of that treaty. The south was therefore Portuguese by treaty and by bull. Then Columbus came back from the west.

What follows is a race between two chanceries. Davenport sets out the documents: shortly after the meeting of 9 March 1493 between Columbus and John II, the king of Portugal fits out a fleet to take possession of the lands found; warned of it, Ferdinand and Isabella send Lope de Herrera to ask that the caravels not sail before it has been decided in which seas those discoveries lay. John II, for his part, sends Rui de Sande to demand that the boundary between the two kingdoms be the parallel of the Canaries, and navigation to the south left to the Portuguese.

The sovereigns of Castile turn to Rome. The bull Inter caetera of 4 May 1493 draws a line a hundred leagues west of the Azores and Cape Verde and gives Castile everything beyond it, on the single condition that no Christian prince had possessed it at Christmas 1492. Davenport notes two things: that bull does not name Portugal, and it was backdated by several weeks since it was not issued until June. On 26 September, Dudum siquidem goes further still and revokes the earlier concessions to Portugal for lands it does not already hold. Portugal finds the hundred leagues too narrow, because its ships are constantly sailing towards those islands, and wants a meridian halfway between Cape Verde and the lands of Columbus. Barcelona in August 1493, a Castilian embassy in November, Medina del Campo in March 1494: three months later, Tordesillas.

That is the hole in the treaty, and the historian who published the text says so plainly: in the state of knowledge at the time it was impossible to determine the position of the dividing meridian, so that the treaty produced new disagreements and its interpretation was disputed into the modern period. Davenport names two causes. The treaty says the Cape Verde Islands without choosing one, and Portugal claimed, according to the period and to its interests, one island of the archipelago rather than another as the starting point of the measurement. And the number of leagues in a degree was itself argued over.

Hence the impossibility of a clean figure in kilometres. The treaty fixes 370 leagues, nowhere says what a league is worth, and allows the distance to be calculated “by degrees, or by any other manner as may be considered the best and readiest”. The sixteenth-century tables Harrisse cites do not agree: fifteen leagues to a degree in France, sixteen and two thirds or seventeen and a half in Spain for a degree of a great circle, seventeen and a half for a Portuguese pilot. Converting the 370 leagues therefore means choosing a league, and the line moves several hundred kilometres depending which one is chosen. Better to say so than to settle it.

The measuring voyage never happened. The two crowns did not apply the ten-month clause, Davenport notes; an agreement signed on 7 May 1495 puts off the sailing of the caravels and orders the line to be marked on all hydrographic charts made in either kingdom. Its main provisions were not carried out either, and it seems neither king planned an expedition to fix the line before 1512. The oldest surviving map that draws it is the so-called Cantino planisphere, of 1502: a blue stroke there carries the legend “Este he o marco dantre castella i portuguall”. Harrisse puts it at 62 degrees 30 west of the Paris meridian and calculates that at sixteen and two thirds leagues to the degree that places the bound about 480 leagues from the westernmost of the Cape Verde Islands, not 370.

In 1500 the line stops being an abstraction. Davenport tells the sequence: Vicente Yáñez Pinzón, then shortly after Diego de Lepe, formally take possession of the coast of Brazil for Castile; nearly three months later Pedro Álvares Cabral, on his way to India, makes land there at about 16 degrees south. That portion of South America stuck out on the eastern side of the line, the Portuguese side, and the treaty had already settled the case: what a Castilian ship finds on that side goes to the king of Portugal and must be handed over at once. The UNESCO file says no different: that is the birth of Brazil, its eastern tip falling in the Portuguese zone.

The line was suddenly worth a great deal, and that is probably what moves King Manuel I to ask Rome to confirm the treaty, writes Davenport. The bull Ea quae, of 24 January 1506, charges the archbishop of Braga and the bishop of Viseu with confirming the Treaty of Tordesillas and having it inviolably observed. Nearly twelve years after the signature: the negotiators had sworn never to ask the pope to release them from their agreement, not never to ask him to back it.

The other end of the line cost more still. Both governments evidently took the Tordesillas meridian to run round the Earth, Davenport notes, and that is the assumption in the long negotiations over the Moluccas opened after the Portuguese arrived there in 1512. The conference of Badajoz, in 1524, settles nothing. By the Treaty of Zaragoza, in 1529, the emperor cedes to Portugal, for 350,000 ducats, his rights of possession and trade in the Moluccas and eastwards as far as a meridian 17 degrees east of the spice islands. On that reckoning the Philippines should have gone to Portugal; Spain managed to keep them. As for the line of 1494, it is the Treaty of Madrid of 13 January 1750 that abolishes it, recognising at the same stroke the present configuration of Brazil.

Read the text in full and one thing leaps out: there are only two parties. The treaty assigns to one king or the other, forever, all lands, islands and mainlands “found and discovered already, or to be found and discovered hereafter”, without the people who live there being parties, consulted or even mentioned. The only obstacle the bull of 4 May 1493 knew, on which Castile relied, was that no Christian king or prince had held effective possession of those lands at Christmas 1492. In other words: the criterion of ownership is Christian sovereignty, and an inhabited country falls into the category of the available.

This is not a present-day reading laid over an old text: the bull itself says what it expects of the inhabitants. It orders the sovereigns to send to those lands and islands God-fearing men, learned, skilled and experienced, to instruct the inhabitants in the Catholic faith and train them in good morals, and its preamble speaks of barbarous nations to be overthrown and brought to the faith. The treaty of 1494 does not speak of them at all. It speaks of marks, direct courses, leagues and restitutions between kings.

Finally, that line never bound anyone but the two of them. Davenport writes that the French were the first to push vigorously into the regions the pope, Portugal and Spain meant to exclude them from, that Francis I asserted in 1528 and again in 1533 the principle of freedom of navigation, and that in the second half of the sixteenth century England became the most formidable opponent of Portuguese and Spanish monopoly claims. The UNESCO file describes the same movement: the Iberian monopoly of navigation strongly contested at the end of the sixteenth century, then destroyed in the seventeenth across much of Africa and the Indian Ocean. Tordesillas bound Castile to Portugal. It bound nobody else.