The India Road – Part III

This is the final installment of the article published by the British Historical Society of Portugal in its annual report for 2013, released in June 2014. For context, please read the previous two entries of this three-part series on the background and historical research for The India Road.

The India Road

Portugal in the last quarter of the fifteenth century

Peter Wibaux

Part III – The Harvest

Both Diogo Cão, who travelled as far south as Namibia, and Bartolomeu Dias, who rounded the Cape, sailed down the west coast of Africa. As their expeditions reached the latitudes of the southeast trades, i.e. around 30oS, they encountered the same problem as the Greeks and Romans faced in their attempts to navigate the Mare Clausum.

The South Atlantic has a wind-driven circulation that mirrors the North Atlantic gyre―except in this case, the upper segment of the gyre is the westward flowing South Equatorial Current, the Gulf Stream is replaced by the Brazil current, and the North Atlantic Drift is now the Antarctic Circumpolar Current[1]. The gyre is cyclonic, almost as if two great cogwheels were at work in the Atlantic.

Cão and Dias attempted to progress south tacking against the SE trades, and opposing the north-flowing Benguela, the eastern boundary current that closes the gyre. The results were significant with respect to disease and loss of life. In those days, the Portuguese armadas typically sacrificed at least one ship over the journey, due to the huge death toll caused by lack of food, and to diseases such as scurvy.

The India Road makes the case that the Mathematical Junta postulated an alternative sailing pattern for the South Atlantic, based on the Portuguese scientific understanding of surface current fields and navigation in the northern hemisphere[2]. Pêro d’Alenquer was chief pilot for both Dias and Gama, and he was known to be close to the astronomers that made up the Mathematical Junta, in particular José Vizinho[3].

Although there are no recorded expeditions between those of Dias (1487-88) and Gama (1497-99), by the time Gama sailed the chief pilot was in possession of a new paradigm, which entailed sailing west from Cape Verde with the South Equatorial current practically until the coast of Brazil, followed by a southerly route along the Brazil current, and finally making use of the westerlies at 40oS for a downwind run east for the Cape of Good Hope[4].

The return route from southern Africa followed the Agulhas current, which flows southwest down the Mozambican coast, then past Natal to the Western Cape, after which the Portuguese mariners sailed the Benguela towards the Gulf of Guinea, mirroring the use of the Canaries current to sail south; the final leg, the ‘Volta da Guiné’, had been discovered two decades before Gama’s first voyage.

The importance of the ‘Golfão’, the circular route across the South Atlantic to the Cape, and of the Portuguese role in its inception, cannot be overstated―it became a standard from the start of the XVIth century until the end of the age of sail, when British and American tea clippers were racing each other to Asia.

Fig. 6. Advanced Portuguese cartography: ‘Jorge de Aguiar made me in Lisbon in the year of our Lord Jesus Christ 1492’, announces this first accurate map of the west coast of Africa (Beinecke Library, Yale University).

Fig. 6. Advanced Portuguese cartography: ‘Jorge de Aguiar made me in Lisbon in the year of our Lord Jesus Christ 1492’, announces this first accurate map of the west coast of Africa (Beinecke Library, Yale University).

To these three pillars, a fourth one must be added: trade. The Perfect Prince twice sent delegations by land to Asia to prepare for the arrival of the maritime expedition. The principal objectives were to gain an understanding of navigation in the Indian Ocean, and to acquire intelligence on the nature of trade, with respect to goods, prices, and the disposition of the local rulers to engage in commerce with these new business partners.

The first delegation did not progress past the Near East, in good part due to language difficulties. The second delegation, which consisted of Pêro da Covilhã and Afonso Paiva, was fluent in both Hebrew and Arabic. The two men travelled the conventional route to Rhodes, then south through Egypt and down the Red Sea. They separated in Aden, and Pêro took a dhow across the Arabian Sea to India. His travels then took him to Hormuz and Mozambique, and provided a wealth of information on the monsoon system in the Indian Ocean, as well as data on the range, availability, and cost of spices, and the political balance in western India between Muslims and Hindus.

It is well-documented that the Perfect Prince, ever-impatient, dispatched two men (both Jewish) to search for Pêro da Covilhã and Afonso Paiva. Pêro da Covilhã met these men in Cairo, and José Sapateiro returned to Lisbon thereafter. Once again, no primary historical sources establish whether the king received a report from Pêro, but I believe the strongest indirect evidence of its delivery is provided by Gama’s arrival in Malindi, Kenya, in 1498.

At ‘Melinde’, Vasco da Gama negotiated to bring aboard a pilot with knowledge of the Indian Ocean monsoon, by necessity an Arab or Indian. His request was not for a pilot to India, but specifically to Calicut.

There has been considerable discussion about the pilot’s identity, including speculation that he was Shihab al-Din Ahmad Ibn Majid, the greatest Arab navigator of the XVth century. The diary of Álvaro Velho, echoed by Malhão Pereira, speaks of a ‘Christian pilot’, who in fact turned out to be a Gujarati―the chronicles of the day call him Malemo Canaqua. However the name merely states his profession, since mu’allim (malemo) means pilot in Arabic, and kanaka is the Indian word for astrologer. Ferrand[5] made a compelling argument that the pilot was the Omani Ibn Majid―Salazar was particularly interested in confirming this, given the political kudos of having the greatest Arab pilot ‘giving’ India to the Christian Portuguese.

Later scholars, including the Syrian Ibrahim Khoury and the Portuguese Luis de Albuquerque, reaffirm that the pilot was in fact Gujarati. According to Khoury, ‘by the late 1480’s Ibn Majid confesses that he is old, and no longer able to navigate competently’. Subarmanyam states that the argument was closed with the discovery in the 1980s of correspondence between Lisbon and Florence just after Gama’s return―these letters contain interviews with the Gujarati pilot, who was apparently brought back to Portugal against his will[6].

Fig. 7. The Kamal, known to the Portuguese navigators as ‘tavoletas da India’, or ‘balestilha[7] do mouro’. The string was held between the teeth and the length adjusted to sight the horizon and a reference star such as Polaris. Simple trigonometry, based on the number of knots in the string, was used to determine latitude.

Fig. 7. The Kamal, known to the Portuguese navigators as ‘tavoletas da India’, or ‘balestilha[7] do mouro’. The string was held between the teeth and the length adjusted to sight the horizon and a reference star such as Polaris. Simple trigonometry, based on the number of knots in the string, was used to determine latitude.

Pêro da Covilhã’s journey to India, documented in Conde de Ficalho’s excellent biography from the late XIXth century, centred precisely on Calicut, where the king’s spy found that Islamic influence was sufficiently diluted by Hinduism―a requirement if Catholics were to enter into a business that effectively destroyed the centuries-old Arab trade routes across the Middle East to Venice.

The Perfect Prince died in 1495, without realizing his dream, but not before the treaty of Alcáçovas was replaced in 1494 by the treaty of Tordesillas―this time, the unknown world was divided into two halves along a meridian of longitude. This task was considerably more difficult than the previous one, since there was no accurate way to measure longitude.

Part of the motivation for this new treaty was the expedition of Columbus, and the discovery of lands in America (the Indies) that Spain wished to claim for itself and explore unobstructed. The initial proposal, a line at the longitude of the Azores, was dismissed outright by the Perfect Prince―it would compromise the Portuguese return route from its African possessions.

A second line, 100 leagues west of Cape Verde, was also dismissed, or rather King John’s negotiators[8], armed with a far superior knowledge of Atlantic geography than their Spanish counterparts, moved it 370 leagues west of the Cape Verde islands―the new line passed west of Brazil, enabling that territory to be legally secured by the Portuguese, but more importantly, the whole of the ‘Golfão’, the circular route to the real Indies across the South Atlantic, became Portuguese territory.

King John’s successor, D. Manuel, was known as the Fortunate King. With every piece already in place, from politics to science, from endeavour (Vasco da Gama had been chosen by the Perfect Prince) to intelligence on commerce, it fell to the new king to give the final impulse to the discovery of the maritime route to India. I preface The India Road with a quote from the diary of Álvaro Velho:

In the name of God, Amen.

In the year 1497, did the king, Dom Manoel, first of this name in Portugal, send out to discover four ships, which went in search of spices. The Captain-General was Vasco da Gama, and of the others, in one his brother Paulo da Gama, in the other Nicolau Coelho.

On the twentieth day of May, 1498, Vasco da Gama’s fleet dropped anchor two leagues outside the city of Calicut, on the Indian west coast.

Further Reading[9]

Axelson, E., 1973. Congo to Cape; early Portuguese explorers. Ed. George Woodstock, Faber & Faber, London.

Bensaude, J., 1913. Regimento do Astrolábio de Évora. Sadag Geneva.

Boxer, C.R., 1975. Women in Iberian expansion overseas, 1415-1815. Some facts, fancies, and personalities. Oxford University Press.

Conde de Ficalho, 1898. Viagens de Pêro da Covilhã. Fronteira do Caos, 2008.

Fontoura da Costa, A., 1939. A marinharia dos descobrimentos. Agência Geral das Colónias.

Garcia, J.M., 1999. A Viagem de Vasco da Gama à Índia, 1497-1499. História da Marinha Portuguesa. Academia da Marinha, Lisboa.

Lacy O’Leary, D.D., 1872. How Greek science passed to the Arabs. Routledge & Kegan Paul Ltd., 1979.

Peres, D., 1943. Descobrimentos Portugueses. Portucalense Editora.

Ravenstein, E.G., 1908. Martin Behaim, his life and his globe. George Philip & Son.

Subrahmanyam, S., 1997. The career and legend of Vasco da Gama. Cambridge University Press.

Velho, A., 1497-99. Roteiro da primeira viagem de Vasco da Gama. Agência-Geral do Ultramar, 1969.


[1] Water flow of 200 million m3 per second, triple that of the Gulf Stream and North Atlantic Drift.

[2]There is no support from primary historical sources for this proposition. Rui de Pina, secretary to King John II, indicates that no report from Pêro da Covilhã was ever delivered. Due to D. João II’s supposed policy of secrecy (política do sigilo), it is unlikely that such ideas would be publicly documented, but even if they were, the 1755 earthquake, and the fire that subsequently destroyed the Torre do Tombo archives in Lisbon, would have eliminated such evidence. There is however substantial indirect support for the concept, which to my knowledge has never previously been discussed as a strategic approach.

[3] In The India Road, I introduce a fictional character (Abraham the Astronomer) who is at liberty to engage in dialogue and take actions without violating historical integrity.

[4]The outbound journey is fully described in the diary of Álvaro Velho, subsequently analysed by both Ravenstein and Gago Coutinho.

[5]Ferrand, G., 1927. Encyclopedie de l’Islam. The original article (in French) is from 1922:

[6]Biblioteca Riccardiana, Florence, Codex 1910, fl. 66r (b).

[7] Cross-staff

[8]The Portuguese delegation included the navigator Duarte Pacheco Pereira. A transcription of the treaty may be found at and it has been used as recently as the last century by Chile in an attempt to claim territory in the Antarctic.

[9]Several of the English titles can be found on or specialty stores such as

Some of the Portuguese books may also be located through Abebooks, but if you visit Lisbon, spend a wonderful morning trawling through the alfarrabistas in the old quarter of Trindade, just off the Bairro Alto. Alfarrábio, or old book, gets its name from the IXth century Baghdad philosopher Al-Farabi. It was in one of these stores that I found the diary of Álvaro Velho.

Atmos Fear and The India Road. Quick links for smartphones.

Atmos Fear and The India Road. Quick links for smartphones.


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