Inter caetera, 1493: the pope's line that led to Tordesillas

The parchment ends the way papal bulls did: given at Rome, at St Peter's, in the year of the Incarnation 1493, “quarto nonas Maii”, the fourth day of May, in the first year of the pontificate. Below the text, in the left margin, a chancery clerk wrote “Jun.”. The bull dated 4 May went out of the papal offices several weeks later, in June.1 source1 source

The Encyclopaedia of Portuguese Expansion puts its completion at 28 June 1493. Nobody knows why it was antedated. What it said was new: from the Arctic pole to the Antarctic pole, a line was to run 100 leagues west and south of any of the islands “commonly known as the Azores and Cape Verde”, and every island and mainland beyond it, found or still to be found, was to belong to the kings of Castile and León.2 sources2 sources

Pope Alexander VI addressed it to Ferdinand and Isabella of Castile and Aragon. It bears a date seven weeks after Christopher Columbus landed back in Spain from the Caribbean. Portugal, which had spent most of the century pushing down the coast of Africa, read it as a threat. A year of quarrelling ended with the two crowns drawing a line of their own at Tordesillas, which is the one that left Brazil to Portugal.3 sources3 sources

A bull is a solemn papal letter, named after its lead seal and known by its first Latin words. Portugal had collected several confirming its African voyages. Romanus Pontifex in 1455 and an earlier Inter caetera, issued by Calixtus III in 1456, reserved to Portugal the trade and conquest of the coast from Cape Bojador through Guinea, “as far as to the Indians”.2 sources2 sources

Castile went on claiming Guinea until the Treaty of Alcáçovas of 1479, in which it left Portugal Guinea, Madeira, the Azores and the Cape Verde islands and kept the Canaries for itself. Pope Sixtus IV confirmed the deal in 1481 with the bull Aeterni regis. Every one of these texts was written with Africa in mind.2 sources2 sources

Then Columbus came back from the west. Storms drove him into the Tagus in March 1493 on his way home, and João II told him the islands fell within Portugal's lordship of Guinea; that meeting has its own article. The king prepared a fleet under Francisco de Almeida, and Ferdinand and Isabella, warned of it, asked him to hold it back. They had already sent word to Rome.2 sources2 sources

The pope they turned to was Rodrigo Borgia, born at Xàtiva, near Valencia, in 1431, who had run the papal chancery as vice-chancellor for decades. He was proclaimed pope on the morning of 11 August 1492 and took the name Alexander VI. Davenport describes him as a friend of King Ferdinand, and the bulls he issued for Castile in 1493 were highly favourable to it.2 sources2 sources

Alexander issued a series of bulls, and the dates on them mislead. The first Inter caetera, dated 3 May, gave Castile the lands its envoys had found and would find, if no Christian ruler held them, and it promised that no right already granted to any Christian prince was being taken away. That saving clause protected Portugal's earlier grants.1 source1 source

Two later bulls replaced it. Eximiae devotionis, also dated 3 May but issued in July, gave Castile in its discoveries the same privileges Portugal held in Africa. The second Inter caetera, dated 4 May and issued in June, drew the line. It dropped the general safeguard for Portugal and kept only an exception for lands that a Christian king actually possessed by Christmas 1492.2 sources2 sources

The bull went further than a grant of land. Under pain of excommunication incurred automatically, it forbade anyone of any rank, “even imperial and royal”, to sail beyond the line for trade or any other reason without a licence from the Castilian monarchs. It also ordered them to send “worthy, God-fearing, learned” men to teach the inhabitants the Catholic faith.1 source1 source

The figure of 100 leagues probably came from Columbus. Davenport calls it highly probable, the Encyclopaedia of Portuguese Expansion says he suggested it, and Fernando Columbus later wrote that his father had. Columbus believed that about 100 leagues west of the Azores the ocean itself changed, and he said so in a letter to the monarchs in 1498.3 sources3 sources

He had also noticed his compass needles swing from pointing east of north to west of north there, and thought he had crossed into a new region of the world. How long a league was is less certain. K. Kretschmer, in a German history of the discovery of America published in 1892, took it as four Roman miles of about 1,480 metres each, so roughly 5.9 kilometres. Counting from Santo Antão, the westernmost Cape Verde island, he put the papal line at about 31 degrees west.2 sources2 sources

João II had already set out his own idea of a boundary. His envoy Rui de Sande asked the Castilian monarchs to keep their subjects from fishing south of Cape Bojador and to make the parallel of the Canaries the limit, with the sea south of it left to Portugal. A line of latitude would have left Portugal everything south of the Canaries, however far west.2 sources2 sources

The papal line was a meridian instead, and a close one. Portuguese ships sailed to the Azores and Cape Verde all the time, Davenport explains, and a frontier only 100 leagues out left them too little sea. Dawson reads the words “west and south” in the bull as aimed squarely at Portugal's claim that everything south of Bojador was its own, whichever way it lay.2 sources2 sources

The bull of 26 September, Dudum siquidem, made things worse for Lisbon. It said that if Castilian ships sailing west reached lands in the east that belonged to India, those lands were Castile's too, and it revoked earlier papal grants to Portugal over lands it did not actually hold. Portugal had not yet reached India; Vasco da Gama got there only in 1498.2 sources2 sources

João answered with diplomacy in Castile. His envoys Pero Dias and Rui de Pina reached Barcelona in August 1493 and came home with nothing; Pina, who later wrote the king's chronicle, blamed Castile for stalling until its second fleet sent news. A grand Castilian embassy to Lisbon in November achieved no more. In March 1494 the talks moved to Medina del Campo.2 sources2 sources

There Portugal asked for a meridian much further west, halfway between the Cape Verde islands and the lands Columbus had found. The Aragonese chronicler Jerónimo Zurita, as Davenport summarises him, said João “was certain that within those limits famous lands and things must be found”. The Encyclopaedia of Portuguese Expansion gives two reasons. Ships returning from the Cape of Good Hope had to swing far out into the Atlantic, and the king may also have known or suspected land in the south-west.2 sources2 sources

At Tordesillas, near Valladolid, the Castilian representatives Enrique Enríquez, Gutierre de Cárdenas and Dr Rodrigo Maldonado signed with João's three envoys on 7 June 1494. The pope was not a party. The two crowns agreed a new meridian 370 leagues west of the Cape Verde islands, everything east of it to Portugal and everything west to Castile, and asked Rome only to confirm it.3 sources3 sources

Each crown kept the other's signed copy. The ratification of Ferdinand and Isabella, signed at Arévalo on 2 July 1494, is in the Torre do Tombo, Portugal's national archive in Lisbon, under the reference PT/TT/GAV/17/2/24. João II's, signed at Setúbal on 5 September, is in the Archivo General de Indias in Seville. In 2007 UNESCO added the treaty to its Memory of the World register on a joint Portuguese and Spanish nomination.3 sources3 sources

Nobody knew. The caravels were never sent. On 7 May 1495 Ferdinand and Isabella signed a further agreement for experts to meet on the border and settle how to measure the line, and that was not carried out either. The treaty did not say which Cape Verde island to count from or how many leagues made a degree, and Portugal later chose whichever island suited it at the time.1 source1 source

In 1495 the cosmographer Jaime Ferrer, of Blanes, advised the Castilian monarchs to count from Fogo, the central island, and reckoned the 370 leagues at 18 degrees. Writing in 1897, the historian Henry Harrisse converted Ferrer's line and later ones onto a modern map. They run from about 42 to 50 degrees west, on the north coast of Brazil, and all but one fall east of both mouths of the Amazon.2 sources2 sources

Maps did not settle it. The oldest surviving map showing the line is the Cantino planisphere, copied in Lisbon in 1502. On Portuguese and Spanish charts of 1519, 1527 and 1529 it doubled as the prime meridian. Harrisse reckoned that charts such as those of Diogo Ribeiro, Charles V's chief cartographer, gave Portugal about 520 miles more longitude than Ferrer's reckoning of 1495.2 sources2 sources

The line soon had something to divide. On 22 April 1500 the India fleet of Pedro Álvares Cabral reached the coast now called Brazil, and Cabral claimed it for Portugal. Vicente Yáñez Pinzón had taken possession of part of that coast for Castile about three months earlier, but it lay on Portugal's side of the line. In 1500 and 1501 Gaspar Corte-Real sailed to lands in the north-west Atlantic that the Portuguese also placed on their side, and in 1506, at Manuel's request, Pope Julius II confirmed the treaty.2 sources2 sources

Other kings ignored it. Henry VII of England sent John Cabot west across it, Francis I of France sent Giovanni da Verrazzano, and both countries later founded claims in North America on those voyages. In Dawson's view the bull bound Spain and Portugal “as regards each other”; how far it bound anyone else he left aside.1 source1 source

The harder question was where the line ran on the other side of the globe. Portuguese ships reached the Moluccas, the clove islands of eastern Indonesia, in 1512, and in 1514 Pope Leo X granted Portugal whatever it found sailing east, even beyond the halfway point. The question became practical, Dawson notes, when the expedition of Fernão de Magalhães (Magellan), sailing west for Castile, reached the Philippines. A conference of experts at Badajoz in 1524 failed to agree.2 sources2 sources

Money settled it. By the Treaty of Zaragoza of 22 April 1529, the Emperor Charles V pledged to Portugal, for 350,000 ducats, all his rights in the Moluccas and in the lands and seas as far east as a meridian 17 degrees east of them. On that reckoning the Philippines fell on Portugal's side, but Spain colonised them anyway. Portugal protested in the 1540s and in 1568, and the dispute went quiet only in 1580, when the king of Spain also became king of Portugal.1 source1 source

On paper the line lasted until the Treaty of Madrid of 1750, which annulled the demarcation lines of Alexander VI's bull, Tordesillas and Zaragoza; it let Spain keep the Philippines and denied Portugal any refund of the 1529 price. The border agreed at San Ildefonso in 1777 has its own article.2 sources2 sources

Brazil is the plainest result. UNESCO's register says that moving the line produced Brazil, since the country's eastern side fell in the Portuguese zone. The Encyclopaedia of Portuguese Expansion adds that the treaties of Madrid and San Ildefonso, which replaced Tordesillas, drew borders between Brazil and its Spanish-speaking neighbours that largely survive today.2 sources2 sources

The bull itself has had a longer and harsher afterlife. Some scholars trace the legal “doctrine of discovery”, which courts in several countries used to limit the land rights of indigenous peoples, to papal grants such as Romanus Pontifex and Inter caetera. On 30 March 2023 two Vatican departments answered that argument in a joint statement.1 source1 source

The same statement admitted that the bulls “did not adequately reflect the equal dignity and rights of indigenous peoples” and that colonial powers had used them to justify immoral acts. Closer to home, a pope's line drawn for Castile pushed João II into the negotiation that gave his successors the coast where Cabral landed six years later.3 sources3 sources