The Legacy of Henry the Navigator

The Legacy of Henry the Navigator

For good and for ill, Henry the Navigator helped set the stage for the modern world. Besides finding new trade routes and connecting various peoples, Henry's expeditions began the process of European colonization and the transatlantic slave trade.


5 - 8


Geography, Human Geography, Physical Geography, Social Studies, World History


Henry the Navigator

Illustrated manuscript portrait of a man.

Illustration from Crónicas dos Feitos de Guiné, courtesy National Geographic
Illustrated manuscript portrait of a man.

Born March 3, 1394 in Portu, Portugal, the third surviving son of King John (João) I and Queen Philippa, Prince Henry (Henrique) was better known as Henry the Navigator. He earned his title despite not venturing on many expeditions himself. Henry funded and planned expeditions to satisfy his curiosity, expand the territory and wealth of Portugal, and to spread Christianity. His actions sparked Europe’s age of exploration, which connected the world's people. But his efforts also began the process of European colonization, capitalism, and, ultimately, the transatlantic slave trade.

Until 1249, parts of Portugal, and most of what is now Spain, was a caliphate known as Al-Andalus. A caliphate is an Islamic state ruled by a religious and political leader, or caliph. Muslim Berbers from North Africa invaded and conquered much of the Iberian Peninsula, which had been ruled by the Christian Visigoths, a Germanic people, in the early 8th century. Portuguese independence was won by crusading European Christians who called the effort the Reconquista.

Muslim rule was not the only obstacle to Portugal’s independence. Toward the north, the County of Portugal was subordinate to the Christian kingdom of Castile. Under the rule of King John I, the kingdom of Portugal won its independence from Castile.

In 1415, Portugal invaded and subjugated the Ceuta, a fortified city in Morocco. The invasion was largely carried out by King John’s three oldest sons, including Henry, to earn their knighthood. The conquest was seen as a crusade, a military and religious campaign. The port city had been a haven for pirates, which was used as a justification for the invasion.

Ceuta gave the young prince a unique education. Beyond the pirates, this place supported bustling trade. Henry learned of trade between North African Muslims and West Africans and Indians. This new knowledge about Africa and Asia sparked Henry’s interest in exploration and enterprise.

A devout Christian, Henry was partially motivated by his religious passion. He wanted to defeat Muslims and spread Christianity in an ongoing holy war. He and his brother were raised on tales of the crusades, and he saw himself continuing that tradition. In his religious efforts, Henry hoped to ally himself with Prester John, a legendary—albeit fictional— Christian king who fought against the Muslims surrounding his kingdom, believed to be in Africa or Asia.

Henry’s planned expeditions needed a large investment. Getting the necessary funding was difficult for a relatively poor nation. The nation’s flourishing merchant class, which included a prominent Jewish community, became the funding force for Henry’s costly projects. The Catholic church also provided support.

To fulfill Henry’s ambitions, he brought together mariners, astronomers, ship designers, mathematicians, navigators, and cartographers to Sagres, on Portugal’s southern coast, which became his base of operations. Despite Henry’s strong religious beliefs, his scholars included Jews and Muslims. Much of their geographic knowledge was based on the work of ancient geographer Ptolemy and the Arab scholars who continued his work.

Many of the tools that became essential for open-sea navigation were adaptations of tools used, sometimes by people from different cultures, for other tasks. Henry’s diverse group of specialists was essential to bringing about the use of these instruments for navigating unfamiliar waters. The caravel, the type of ship used for Henry’s nautical activities, was likely based on a type of Portuguese fishing boat. Caravels were small, maneuverable ships. Unlike other Portuguese vessels which used square sails, caravels used triangular, or lateen, sails. This design, likely of Arab origin, allowed ships to sail against the wind. Other instruments adapted for moving in the open ocean were the compass, the hourglass, the quadrant, and the astrolabe. The quadrant is a mechanical device used to measure angles. As a seafaring device, it helped sailors determine their longitude and latitude. The astrolabe calculated the position of planetary bodies.

Henry’s experts at Sagers connected their knowledge with these adapted instruments to pave the way for sailing the West African coast. At the time, no documented European had gone farther south than Cape Bojador, located in what is now Western Sahara (a disputed territory, which has been administered by Morocco since 1979) since the ancient Romans. The current at this part of the coast moves in a southward direction making sailing to Europe difficult. The bigger obstacle may have been superstition. Sailors largely believed the cape was unpassable.

Under the expeditions Henry sponsored, Portugal colonized islands off the coast of West Africa, including the mostly inhabited Canary Islands, as well as the uninhabited islands of the Azores and Madeira.

Henry needed money to keep his expeditions going. The prince had wanted access to West African gold. However, West Africans maintained control of local gold deposits, mainly trading gold dust with the Portuguese during Henry’s life. So instead, the economic push shifted to another resource: enslaved humans. The Portuguese started systematically raiding settlements on the island of Arguin to kidnap local inhabitants. These Africans were enslaved and taken to Lisbon. In 1448, the Portuguese built a fort, warehouse, and a trading station on the island, located off the coast of what is now Mauritania.

In the early 1450s, enslaved Africans were forced to build and labor on sugar plantations in Madeira. Plantation economies focused on a single, cash crop to export to make a profit. This plantation system was repeated in other Portuguese colonies. African captives were taken from the mainland and the Cape Verde Islands, off the coast of Senegal where they were forced to labor.

By the time of Henry’s death, in 1460, the Portuguese had reached what is now Sierra Leone. Many of Henry’s ambitions, however, continued to flourish. The nation’s sailors circumnavigated Africa. The Portuguese established colonies along the west and east coasts of Africa.

In the years that followed, the Portuguese created trading ports as far as Japan. Portuguese navigators also made their way to India. Trade was established with kingdoms along the India Ocean.

During this period, the Portuguese also established colonies in Brazil. Like the Portuguese colonies in West Africa, enslaved Africans were forced to work Brazil’s sugar plantations. With its large-scale forced transportation of captive Africans to the Americas, Portugal, along with competitor Spain, created what became the transatlantic slave trade.

Henry’s legacy, like the man, is a complex one. While he opened trade and connected various peoples and cultures, his colonization efforts sparked some of humanity’s greatest atrocities. Historically, colonization has caused a loss of resources, land, life, religion, culture, and autonomy for the indigenous people being colonized. Colonies have been established to enrich the colonizers with little, if any, consideration to the peoples already living there. This attitude became apparent with the signing of the Treaty of Tordesillas in 1495. Fearing Spain’s colonization efforts would encroach on its own, Portugal divided claims on the Western Hemisphere between the two nations. This included future claims with no regard or consultation from the Indigenous nations and populations this would involve.

Media Credits

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Tyson Brown, National Geographic Society
National Geographic Society
Production Managers
Gina Borgia, National Geographic Society
Jeanna Sullivan, National Geographic Society
Program Specialists
Sarah Appleton, National Geographic Society, National Geographic Society
Margot Willis, National Geographic Society
Clint Parks
Roza Kavak
Last Updated

October 19, 2023

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