In 1434, the Portuguese navigator Gil Eanes sailed past Cape Bojador (in present-day Western Sahara). This mattered because European sailors had long treated the cape as a practical and psychological barrier. Rounding it helped open sustained Portuguese voyages farther down the West African coast.
In 1441, a Portuguese caravel returned from the West African coast with gold dust and enslaved people. The cargo helped convince critics in Portugal that the new voyages could pay for themselves. It also signaled that exploration was quickly becoming tied to trading and raiding.
By 1443, Portuguese voyages had reached the Bay of Arguin, a key area for coastal trade and contact. These visits helped turn intermittent sailing into a more regular system of stops along the coast. Arguin soon became one of Portugal’s main early hubs for exchanging goods—and for human trafficking.
In 1445, Portuguese explorer Dinis Dias reached the mouth of the Senegal River. The voyage pushed Portuguese knowledge farther south along the coast and improved European mapping of West Africa. It also strengthened Portugal’s ability to find coastal trading opportunities without relying on overland routes.
In 1446, Nuño Tristão sighted the Gambia River, another major waterway and point of contact. Each new river reached meant more information about winds, currents, and sailing distances. This knowledge reduced risk and supported continued voyages farther down the coast.
By 1448, the trade in enslaved people to Portugal had grown enough that Prince Henry ordered a fort and warehouse on Arguin Island. The fort functioned as a protected trading post (often called a forte-feitoria). It marked a shift from exploration alone to building infrastructure to control commerce.
In 1452, Pope Nicholas V issued the bull Dum Diversas, which supported Portugal’s campaigns against non-Christians and included language that was later used to justify enslavement. This mattered because it gave religious and legal backing to actions already taking place on the African coast. It helped shape the ideas used to defend Portuguese expansion and forced labor.
In 1455, Romanus Pontifex reinforced Portuguese claims to exclusive rights to explore and trade along parts of the African coast. It aimed to limit interference by other Christian powers while framing expansion as tied to spreading Christianity. This strengthened Portugal’s political position as its voyages became more profitable.
Around 1456, Prince Henry sent Diogo Gomes to investigate the West African coast. Gomes sailed beyond the Gêba River and later traveled up the Gambia River, reporting encounters with inland trade networks. These voyages show how Portuguese objectives were expanding from coastal scouting toward gathering intelligence about regional commerce.
Prince Henry died on November 13, 1460. Although he did not sail on most voyages himself, he was a central organizer and patron for early exploration along West Africa. His death marked a leadership transition, but the system of exploration and trading he helped build continued to expand.
In 1469, King Afonso V leased much of the Guinea trade monopoly to the Lisbon merchant Fernão Gomes for an annual payment. The contract also required exploration of 100 leagues of African coast each year, linking private profit to continued discovery. This policy helped finance voyages while pushing exploration farther into the Gulf of Guinea.
In 1471, Portuguese voyages under João de Santarém and Pêro (Pedro) Escobar reached the area associated with the gold trade later centered at Elmina (São Jorge da Mina). This discovery mattered because it redirected Portuguese attention toward securing a steady supply of West African gold. It also set the stage for building a permanent fortress to protect and control the trade.
On September 4, 1479, Portugal and Castile signed the Treaty of Alcáçovas, later ratified in Toledo on March 6, 1480. Among other terms, it recognized Portuguese rights in key Atlantic and African areas while confirming Castilian control of the Canary Islands. This reduced major Iberian rivalry and supported Portugal’s ability to pursue West African expansion with less risk of conflict.
In 1482, the Portuguese built Elmina Castle (Castelo de São Jorge da Mina) on the Gold Coast (in present-day Ghana). It was designed to protect and control the gold trade and became a major Portuguese base in the region. The fortress marked a clear shift from exploratory voyages to permanent European-built fortifications in West Africa.
In August 1482, navigator Diogo Cão became the first European known to reach the mouth of the Congo River. He erected a stone pillar (a padrão) to mark Portuguese presence and began contacts for trade. This expanded Portuguese exploration beyond earlier West African routes and signaled new ambitions farther south.
Early Portuguese exploration of the West African coast (1434–1482)