Armada of the Strait of Magellan (1581-1584)

In 1520, the Portuguese navigator Ferdinand Magellan, in command of a small Spanish fleet, used for the first time a sea route in the far south of the American continent which connected the Atlantic and Pacific Oceans. The proof of the existence of this inter-oceanic passage, which became known as the Strait of Magellan in honour of the Portuguese navigator, demonstrated that all the continents were united by the sea.

During the period of dynastic union, the kingdoms of Portugal and Castile aligned themselves, sharing, among other things, aspects related to the best way to defend their American territories. The expansion of a strategy towards the Atlantic was reinforced with the Lusitanian incorporation. The Strait of Magellan, due to its strategic location, together with the commercial and political monopoly of the region, represented an important space to be defended since it would protect both the Atlantic and Pacific Oceans from the presence of rival nations. However, its geographical position brought with it other problems as the region was difficult to navigate. This obstacle in the “Estrecho de la muerte[1]”, as Lope de Vega called it, prevented the region from being occupied. After its discovery, the expeditions to the Strait were only reconnaissance ones, due to the difficulty of entering the territory.

The Strait of Magellan, relatively forgotten during the reign of Charles V, became an important issue for Philip II due to Francis Drake’s passage through the region. In 1579, the English corsair reached the Pacific Ocean by crossing the Strait of Magellan in an east-west direction. Finding the coasts of Castile’s possessions in the region unguarded, Drake attacked ports in Chile and Peru. It was then that Philip II, in 1581, ordered two forts to be built in the region “para la seguridad del Estrecho de Magallanes y para que los corsarios que le han descubierto no se apoderen de él, como se entiende que procuran hacerlo[2]”.

Pedro Sarmiento de Gamboa, Spanish navigator, was appointed by Philip II as governor of the lands of the Strait of Magellan, in an expedition that would leave Spain towards the southernmost tip of the American continent. Sarmiento, the main organiser of the mission to the Strait, would hold the post when the territory was settled. Sarmiento would be responsible for the colonisation and construction of forts at the Atlantic entrance to the Strait. The importance of the maritime enterprise required a qualified commander, which made Felipe II decide for Captain-General Diego Flores de Valdés, one of the most prominent and experienced navigators of the Spanish navy, with over thirty years of service to the Crown.

Preparations for the Armada of the Straits of Magellan lasted throughout the first half of 1581. The military armadas of the Habsburg period represented concrete projects of political action. There was not a single, main royal armada, designated as such, but multiple missions, with distinct aims and financing. The armadas were organised on a transitional basis, almost always in places that threatened the sovereignty of the monarchy, as was the case of the Straits of Magellan. Although the construction of forts and the colonization of the lands of the Strait were expressly included in the royal recommendations[3], the military character of the journey was predominant and the armada had to prioritize the pursuit and punishment of the corsairs and the destruction of any fortified places that had been established by them along the Atlantic coast.

According to the king’s instructions, the true objective of the expedition was to be kept secret, both so that the undertaking would not come to the knowledge of non-American nations and so as not to hinder the recruitment of those who would embark, considering that the adverse conditions in the vicinity of the Strait were already known to the sailors. The greatest obstacles to the preparatory work for the expedition arose from the scarcity of resources of the Crown to provide the necessary artillery and equipment for the undertaking. However, for Pierre Chaunu, the insufficient number of ships in the Spanish Atlantic fleets to meet the demands of the enterprise caused greater obstacles to the mounting of the expedition than the financial difficulties the kingdom was experiencing at the time (Chaunu, 1955: 295-296).

The recruitment of around two thousand five hundred men for the Armada del Estrecho suffered several tribulations, considering that many of them served in the troops that Spain maintained in Italy and Flanders and a significant contingent participated, at the time, in the Spanish commercial fleets. The low remuneration and the secrecy surrounding the enterprise, with the possibility of a dangerous journey, discouraged recruitment. Coetaneous documents show that components of fleets returning to Spain had to be forcibly transferred from the ships where they were to the navy vessels, and a group of 280 recruits had to be imprisoned to prevent the soldiers from deserting until the expedition left (Phillips, 2016: 26).

Finally, the armada was made up of 23 ships, only four of which belonged to the Crown. The others were rented from their owners against monthly payments based on the tonnage capacity of the ships, totalling 8,400 tons contracted. There were 1,332 soldiers, 672 sailors, 670 men who were going to Chile with the governor of the territory, 206 “colonos” with wives and children who would settle in the Strait, plus artillerymen, blacksmiths, carpenters and others. The Admiral, the second-in-command of the fleet, was Diego de la Rivera[4], Asturian like most of the members of the fleet. Diego Flores de Valdés, Pedro Sarmiento, the governor of Chile, Alonso de Sotomayor[5], as well as royal officers, the auditor, the provost, the clerk, friars and the engineer Bautista Antonelli participated in the expedition. They totalled around 3,500 people[6].

After several delays and in compliance with the king’s determination that the fleet should start its journey as soon as possible, the Duke of Medina Sidonia, capitán general del mar de Andalucia, set 25 September 1581 as the date for the departure of the expedition, leaving from the port of Sanlúcar de Barrameda, the base of operations for the expedition. Until then, the destination of the squadron was unknown to most of those who were about to travel. The date chosen disregarded warnings that were made by the pilots about the impropriety of that decision, due to the fact that the days following the equinox would have a higher incidence of strong storms.

Five ships left on September 25, six the next day, and on September 27 the galleaza capitana and the other vessels of the fleet left the port of Sanlúcar de Barrameda. After six days of sailing with favourable winds, when the fleet was in the vicinity of Cádiz, about 110 miles from Sanlúcar, a strong storm brought harmful consequences for the expedition. Four vessels sank and many ships were damaged. According to Pedro Sarmiento de Gamboa, approximately 800 people died in that tragedy. Provisions, arms and ammunition were also lost. The misfortune directly affected Diego Flores de Valdés, as several of his family members and military personnel who had accompanied him for years in his life at sea died in the episode (Sarmiento de Gamboa, 1895: 234).

Back in Cádiz, work to recover the ships and the armaments lost during the storm continued until mid-November. On November 23, Felipe II ordered the departure of the expedition to Rio de Janeiro, where it was to remain until October of the following year, awaiting favourable navigation conditions for the Strait. Everything was ready for the fleet to leave Cádiz Bay on December 2. When everyone was already on board, a heavy storm began which lasted four days, hitting the ships with such intensity that the frigate Guadalupe sank. As the weather improved, the expedition finally left Cádiz on the morning of 9 December.  The armada of the Strait of Magellan was then down to sixteen vessels with 2,408 people on board (Phillips, 2016: 37).

After a month of sailing, the fleet landed on the island of Santiago, in Cape Verde, a stopping point for the ships crossing the Atlantic. Considering that the expedition was going to stay a few days in Santiago and there was a caravel on the way to Brazil, Diego Flores de Valdés, aware of the main purpose of the expedition, sent letters to the governors of Bahia and Pernambuco. The content of the correspondence referred specifically to requests for information on the state of the Brazilian coast with regard to Corsican incursions and pacification of the land. The governors were to send the news to Rio de Janeiro, to where the armada would then move. It is clear, even before arriving in Brazil, the concern of Valdés with the state of the Brazilian coast, target of French raids in search of “pau-brasil”.

With the reinforcement of provisions (and desertions), the fleet left Cape Verde on February 2, 1582. After 53 days of navigation, with many sick people and more than 150 deaths along the way, due to diseases related to the precarious food and salubrious conditions of the ships, the fleet arrived in Rio de Janeiro, which at that time was a small town without many resources to receive such a large contingent of people. With many sick people in the armada, according to Sarmiento’s account, the settlers who lived in the settlement offered to treat the most seriously ill. Even with all the help, 150 died and others, seeing the situation, deserted (Sarmiento de Gamboa, 1895: 242). Diego Flores de Valdés, considering the precariousness of the place to supply the needs of the armada during the period in which they would be awaiting departure for the south of the Atlantic, sent a mission to the then wealthier and older city of São Vicente to obtain the required provisions (Vilardaga, 2010: 67). The armada remained in Rio de Janeiro for more than seven months as it awaited, in addition to the favorable time to continue the trip to the Strait, the reinforcement of supplies promised by Felipe II, upon the departure of the armada from Spain.

Finally the fleet of provisions and supplies commanded by Captain General Diego de Alcega arrived in Rio de Janeiro. The main commanders of the expedition decided that a new attempt to take Pedro Sarmiento and his colonists to the Strait would be made with part of the armada with 5 ships under the command of Admiral Diego de la Rivera and with the addition of 500 men, in addition to 140 of Sarmiento. Despite the summer, weather conditions prevented the vessels from entering the mouth of the Strait. Once again, Pedro Sarmiento’s second attempt to land in the Strait of Magellan ended in failure. Concomitantly to this, Diego Flores de Valdés would sail to Bahia, as already planned, to fight the French who had settled in Paraíba (Phillips, 2016: 44-46). The conquest of Paraíba, attempted so many times by the Portuguese, only succeeded with the action of the Armada do Estreito, organised as an initiative of the Habsburgs. Due to its privileged geographical location, Paraíba represented an important military vector in the Habsburg defensive planning.

The Fleet of the Straits of Magellan was successful beyond the Straits. Its objectives included defending the American continental territory against the threat of corsairs and guaranteeing Brazil’s loyalty to Philip II. To study the Armada del Estrecho is to understand the historical importance of the struggles for the defence of American territories in the southern hemisphere, which had almost always been treated as secondary within this complex mosaic that was the Hispanic Monarchy.

[1] “La Dragontea” (1598), Lope de Vega.

[2] AGS, Archivo General de Simancas, Mar y Tierra, legajo 117.

[3] AGI, Archivo General de Indias, Real Cédula. Indiferente, 582, L. 1, f. 29v-31v.

[4] AGI, Archivo General de Indias, Real Cédula. Indiferente 582, L. 1, f. 33-33v.

[5] AGI, Archivo General de Indias, Real Cédula. Indiferente, 582, L.1, f.29v.

[6] AGI, Archivo General de Indias, Consulta del Consejo de Indias. Indiferente, 739, N. 306.


  • Brito, S. B. R. (2020). A conquista do rio ruim. A Paraíba na Monarquia Hispânica (1570-1630). Tese de Doutorado, Universidade de Salamanca, Salamanca.
  • Chaunu, P.; Chaunu, H. (1955). Huguette Chaunu. Seville et l’Atlantique, 1504-1650. Vol 3. Paris: Armand Colin.
  • Fernandez Duro, C. (1897). Historia de la Armada española desde la unión de los Reinos de Castilla y Aragón. Tomo II. Madrid: Establecimiento tipográfico Suc. Rivadeneyra.
  • Phillips, C. R. (2016). The struggle for the South Atlantic: the Armada of the Strait, 1581-1584. Abingdon, Oxon; New York, NY: Routledge, for the Hakluyt Society.
  • Sarmiento de Gamboa, P. (1895). Narratives of Voyages to the Straits of  Magellan, translated and edited with notes and an introduction by Clemens R. Markham. C.B., F.R.S. London: Hakluyt Society.
  • Vilardaga, J. C. (2010). São Paulo na órbita do império dos Felipes: conexões castelhanas de uma vila da América portuguesa durante a União Ibérica (1580-1640). Tese de doutorado apresentada à Universidade de São Paulo.


Sylvia Brito (Biblioteca Nacional do Brasil)

How to quote this entry:

Sylvia Brito. “Armada of the Strait of Magellan (1581-1584)“. In: BRASILHIS Dictionary: Biographic and Thematic Dictionary of Brazil in the Spanish Monarch (1580-1640). Available in: Date of access: 13/04/2024.

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