Infante Dom Henrique de Avis, Duke of Viseu (4 March 1394 – 13 November 1460), better known as Henry the Navigator was an important figure in 15th-century Portuguese politics and in the early days of the Portuguese Empire. Through his administrative direction, he is regarded as the main initiator of what would be known as the Age of Discoveries. Henry was the fifth child of the Portuguese king John I and responsible for the early development of Portuguese exploration and maritime trade with other continents through the systematic exploration of Western Africa, the islands of the Atlantic Ocean, and the search for new routes.

King John I was the founder of the House of Aviz. Henry encouraged his father to conquer Ceuta (1415), the Muslim port on the North African coast across the Straits of Gibraltar from the Iberian Peninsula. He learnt of the opportunities from the Saharan trade routes that terminated there, and became fascinated with Africa in general; he was most intrigued by the Christian legend of Prester John and the expansion of Portuguese trade. Henry is regarded as the patron of Portuguese exploration.

Henry was the third surviving son of King John I and his wife Philippa, sister of King Henry IV of England. He was baptized in Porto, and may have been born there, probably when the royal couple was living in the city’s old mint, now called Casa do Infante (Prince’s House), or in the region nearby. Another possibility is that he was born at the Monastery of Leça do Bailio, in Leça da Palmeira, during the same residential passage of the royal couple in the city of Porto.

Henry was 21 when he, his father and brothers captured the Moorish port of Ceuta in northern Morocco, that had long been a base for Barbary pirates who raided the Portuguese coast, depopulating villages by capturing their inhabitants to be sold in the African slave market. Following this success, Henry started to explore the coast of Africa, most of which was unknown to Europeans. His objectives included finding the source of the West African gold trade and the legendary Christian kingdom of Prester John, and stopping the pirate attacks on the Portuguese coast. At that time the ships of the Mediterranean were too slow and too heavy to make these voyages. Under his direction, a new and much lighter ship was developed, the caravel, which could sail further and faster, and, above all, was highly maneuverable and could sail much nearer the wind, or into the wind. This made the caravel largely independent of the prevailing winds, and enabled her to explore the shallow waters and rivers as well as the open ocean with wide autonomy. In 1419, Henry’s father appointed him governor of the province of the Algarve.

On 25 May 1420, Henry gained appointment as the Grand Master of the Military Order of Christ, the Portuguese successor to the Knights Templar, which had its headquarters at Tomar, in central Portugal. Henry would hold this position for the remainder of his life, and the order was an important source of funds for Henry’s ambitious plans, especially his persistent attempts to conquer the Canary Islands, which the Portuguese had claimed to have discovered before the year 1346.

In 1425, his second brother the Infante Peter, Duke of Coimbra, made a tour of Europe. While largely a diplomatic mission, among his goals was to seek out geographic material for his brother Henry. Peter left Venice with a current world map drafted by a Venetian cartographer.

In 1431 he donated houses for the Estudo Geral to reunite all the sciences — grammar, logic, rhetoric, arithmetic, music and astronomy — into what would later become the University of Lisbon. For other subjects like medicine or philosophy, he ordered that each room should be decorated according to each subject that was being taught.

Henry also had other resources. When John I died in 1433, Henry’s eldest brother, Edward became king, and granted Henry all profits from trading within the areas he discovered as well as the sole right to authorize expeditions beyond Cape Bojador. He also held a monopoly on tuna fishing in the Algarve. When Edward died eight years later, Henry supported his brother Peter for the regency during Afonso V’s minority, and in return received a confirmation of this levy.

Henry functioned as a primary organizer of the disastrous expedition to Tangier in 1437. Henry’s younger brother Ferdinand was given as a hostage to guarantee that the Portuguese would fulfill the terms of the peace agreement that had been made with Çala Ben Çala. The Portuguese Cortes refused to approve the return of Ceuta in exchange for the Infante Ferdinand who remained in captivity until his death six years later.

Prince Regent Peter had an important role and responsibility in the Portuguese maritime expansion in the Atlantic Ocean and Africa during his administration. Henry promoted the colonization of the Azores during Peter’s regency (1439–1448).

For most of the latter part of his life, Henry concentrated on his maritime activities, or on Portuguese court politics.

According to João de Barros, in the Algarve he repopulated a village that he called Terçanabal (from terça nabal or tercena nabal). This village was situated in a strategic position for his maritime enterprises and was later called Vila do Infante (“Estate or Town of the Prince”).

It is traditionally suggested that Henry gathered at his villa on the Sagres peninsula a school of navigators and map-makers. However modern historians hold this to be a misconception. He did employ some cartographers to chart the coast of Mauritania after the voyages he sent there, but there was no center of navigation science or observatory in the modern sense of the word, nor was there an organized navigational center.

Referring to Sagres, sixteenth century Portuguese mathematician and cosmographer, Pedro Nunes, remarked, “”from it our sailors went out well taught and provided with instruments and rules which all map makers and navigators should know.”

The view that Henry’s court rapidly grew into the technological base for exploration, with a naval arsenal and an observatory, etc., although repeated in popular culture, has never been established. Henry did possess geographical curiosity, and employed cartographers. Jehuda Cresques, a noted cartographer, has been said to have accepted an invitation to come to Portugal to make maps for the infante. This last incident probably accounts for the legend of the School of Sagres, which is now discredited.

The first contacts with the African slave market were made by expeditions to ransom Portuguese subjects enslaved by pirate attacks on Portuguese ships or villages. As Sir Peter Russell remarks in his biography, “In Henryspeak, conversion and enslavement were interchangeable terms.”

Henry sponsored voyages, collecting a 20% tax (o quinto) on the profits made by naval expeditions, which was the usual practice in the Iberian states of that time. The nearby port ofLagos provided a convenient harbor from which these expeditions left. The voyages were made in very small ships, mostly the caravel, a light and maneuverable vessel that used thelateen sail which had been the prevailing rig in Christian Mediterranean navigation since late antiquity. Most of the voyages sent out by Henry consisted of one or two ships that navigated by following the coast, stopping at night to tie up along some shore.

During Prince Henry`s time and after, the Portuguese navigators discovered and perfected the North Atlantic “Volta do Mar” (the turn of the sea or return from the sea). This was a major step in the history of navigation, when an understanding of winds in the age of sail was crucial to Atlantic navigation, from Africa and the open ocean to Europe, and enabling the main route between the New World and Europe in the North Atlantic, in future voyages of discovery. Understanding the Atlantic gyre and the volta do mar enabled them to beat upwind to the Strait of Gibraltar and home, after navigating favorably to the south and southwest, towards the Canary Islands or the southwest. The pilots first had to sail far to the west — counter-intuitively, in the wrong direction, that is, farther from continental Portugal, then for northeast, to the area around the Azores islands, and to east — in order to catch usable following winds, and return to Europe. Christopher Columbus would use it on his transatlantic voyages.

Madeira

The first explorations followed not long after the capture of Ceuta in 1415. Henry was interested in locating the source of the caravans that brought gold to the city. During the reign of his father, King John, João Gonçalves Zarco, and Tristão Vaz Teixeira were sent to explore along the African coast. Zarco, a knight in service to Prince Henry had commanded the caravels guarding the coast of Algarve from the incursions of the Moors. He had also been at Ceuta.

In 1418, Zarco and Teixeira, were blown off-course by a storm while making the volta do mar westward swing to return to Portugal. They found shelter at an island they named Porto Santo. Henry directed that Porto Santo be colonized. The move to claim the Madeiran islands was probably a response to Spain’s efforts to claim the Canary Islands. In 1420, settlers then moved to the nearby island of Madeira.

The Azores

A chart drawn by the Catalan cartographer, Gabriel de Vallseca of Mallorca has been interpreted to indicate that the Azores were first discovered by Diogo de Silves in 1427. In 1431, Gonçalo Velho was dispatched with orders to determine the location of “islands” first identified by Diogo de Silves. Velho apparently got a far as the Formigas, in the eastern archipelago, before having to return Sagres, probably due to bad weather.

By this time the Portuguese navigators had also reached the Sargasso Sea (western North Atlantic region), naming it after the Sargassum seaweed growing there (sargaço / sargasso in Portuguese).

African coast

Until Henry’s time, Cape Bojador remained the most southerly point known to Europeans on the desert coast of Africa. Seafarers superstition held that beyond the cape lay sea monsters and the edge of the world. In 1434, Gil Eanes, the commander of one of Henry’s expeditions, became the first European known to pass Cape Bojador.

Alvise Cadamosto explored the Atlantic coast of Africa and discovered several islands of the Cape Verde archipelago between 1455 and 1456. In his first voyage, which started on 22 March 1455, he visited the Madeira Islands and the Canary Islands. On the second voyage, in 1456, Cadamosto became the first European to reach the Cape Verde Islands. António Noli later claimed the credit. By 1462, the Portuguese had explored the coast of Africa as far as the present-day nation Sierra Leone. Twenty-eight years later, Bartolomeu Dias proved that Africa could be circumnavigated when he reached the southern tip of the continent, now known as the “Cape of Good Hope.” In 1498, Vasco da Gama became the first European sailor to reach India by sea.