Portugal seized Ceuta on the North African coast, gaining a strategic foothold near long-established trans-Saharan caravan routes. The conquest helped focus Portuguese leaders on finding new ways to access West African gold and other goods without relying on intermediaries across the Sahara.
Portuguese captains opened regular trade contacts along the Senegal River region, exchanging Mediterranean goods for gold and enslaved people. These coastal connections expanded commerce that had long been tied to trans-Saharan networks, but now with ships linking directly to Atlantic ports.
Portuguese builders established an early fortified base on Arguin Island, used for Atlantic trade and as a staging point along the West African coast. The exact start date is debated in the sources, but Arguin clearly became part of a growing chain of coastal posts that competed with Saharan overland routes.
Portuguese voyages reached the area they called “Mina” (near present-day Elmina, Ghana), where gold was already moving through African trade systems. Direct access by sea made it easier for European merchants to buy gold on the coast rather than through trans-Saharan caravan chains that linked West Africa to North Africa and the Mediterranean.
Portugal and Castile signed the Treaty of Alcáçovas, which helped formalize Portuguese control over key Atlantic island groups and rights tied to the Guinea trade. This diplomatic settlement supported Portugal’s continued push down the African coast and strengthened the sea-based alternative to Saharan commerce.
Portugal constructed Elmina Castle (São Jorge da Mina) as a fortified factory (trading post) to protect and organize the coastal gold trade. The fort anchored Portuguese influence on the Gulf of Guinea and helped pull parts of the gold trade toward Atlantic shipping rather than northward trans-Saharan routes.
Bartolomeu Dias became the first European navigator to round the southern tip of Africa. This proved that Atlantic ships could reach the Indian Ocean, strengthening the long-term logic of sea routes that reduced dependence on overland Eurasian and Saharan trade corridors.
Spain and Portugal signed the Treaty of Tordesillas, setting a line of demarcation for exploration and claims. The agreement backed Portugal’s continued investment in Atlantic and African routes, which increasingly competed with older trans-Saharan pathways for high-value trade.
Vasco da Gama reached India using an ocean route around Africa, linking Europe and Asia by sea. As Portuguese shipping expanded, trade increasingly shifted to maritime routes that bypassed caravan systems, weakening the strategic position of inland trans-Saharan entrepôts over time.
In the late 1500s, internal struggles and succession disputes weakened the Songhai Empire, which had benefited from taxing and protecting Saharan caravan trade. Political instability reduced security and predictability for long-distance overland commerce at the same time Atlantic competition was rising.
Moroccan forces defeated Songhai at the Battle of Tondibi using gunpowder weapons, accelerating Songhai’s collapse. The conflict disrupted the political order that had supported trans-Saharan trade routes through cities like Gao and Timbuktu.
After the 1591 victories, Moroccan forces captured Timbuktu and established a new administration often described as the Pashalik of Timbuktu. Instead of restoring trans-Saharan prosperity, the occupation and continued conflict contributed to fragmentation and reduced the region’s ability to compete with Atlantic trade flows.
During the Dutch–Portuguese War, the Dutch captured Elmina Castle, a key hub in Atlantic commerce on the Gold Coast. Control shifted from Portugal to the Dutch West India Company, showing how Atlantic competition had become central while trans-Saharan routes faced political disruption and changing demand patterns.
Portuguese Atlantic Expansion and the Disruption of Trans-Saharan Routes (c. 15th–17th centuries)