By the early 1470s, Portuguese voyages reached what Europeans later called the Gold Coast (in present-day Ghana) to trade, especially for gold. This early trade set the stage for permanent coastal bases meant to secure commerce and project military power. These bases later became key points in Atlantic slave exports.
In 1482 the Portuguese built Elmina Castle (Castelo de São Jorge da Mina) to protect and control coastal trade, especially gold. It became a fortified headquarters for Portuguese commerce on the coast. Over time, it also became a major holding and shipping point for enslaved Africans.
In late August 1637, Dutch forces captured Elmina from Portugal during the Dutch–Portuguese conflicts. Control of this major castle helped the Dutch expand their influence along the Gold Coast’s fort-and-castle trade system. The change mattered because these forts were not just warehouses—they were armed hubs shaping prices, alliances, and access to trade, including enslaved people.
In 1649 the Dutch built Fort Crèvecoeur (later known as Ussher Fort) in Accra as part of their Gold Coast defensive-trading network. This fort system supported long-distance Atlantic commerce by providing secure places to store goods and hold captives. Such forts increased European leverage in coastal trade and helped sustain slave exports.
In the 1660s, Denmark–Norway built and expanded Fort Christiansborg (Osu Castle) in Accra, which later served as the capital of the Danish Gold Coast. From this base, Danish authorities and merchants participated in Atlantic trade, including the overseas shipment of enslaved people. The castle illustrates how multiple European powers competed through fortified sites rather than inland conquest alone.
By the mid-1600s, Cape Coast Castle developed into a major English fortified trading post on the Gold Coast. Over time, it became a central base for English commercial activity supported by other smaller forts. This coastal fort system helped organize exports, including people sold into Atlantic slavery.
In 1672, England chartered the Royal African Company to run a fortified trade system on the West African coast. Its operations relied on castles and forts, with Cape Coast Castle as a key headquarters, to manage trade flows and security. The company became deeply involved in the trafficking of enslaved Africans to English colonies in the Americas.
In 1792, Denmark–Norway decided to end its legal participation in the transatlantic slave trade, with the ban set to take effect in 1803. The long delay shows how governments often tried to balance profits, colonial demands, and growing political pressure. Even with legal bans, illegal trading and smuggling continued elsewhere, keeping pressure on coastal forts and routes.
On 25 March 1807, Britain passed the Slave Trade Act, banning British involvement in the Atlantic slave trade (it took effect on 1 May 1807). This did not end slavery in British colonies immediately, but it changed enforcement priorities and increased naval patrols. British policy shifts gradually made many coastal forts less profitable as slave-export depots, while also increasing conflict over control and customs revenues.
In 1808, Britain established the Royal Navy’s West Africa Squadron to suppress the Atlantic slave trade by patrolling the West African coast. The squadron’s presence affected coastal shipping patterns and raised the risks and costs for slave traders. Its actions became part of a broader push that increasingly linked fort control with anti-slave-trade policing and imperial expansion.
On 6 March 1844, the Bond of 1844 was signed between British officials and several Fante leaders. It helped formalize British influence by shaping how law and justice were administered in areas tied to coastal trade. This mattered for forts and castles because it supported a shift from commerce-only relationships toward more direct colonial governance.
In 1850, Denmark sold its forts on the Gold Coast—including Christiansborg—to Britain. This transfer strengthened Britain’s position along a coastline where forts controlled harbors, taxation points, and local alliances. Consolidation under British control also connected fort management more tightly to British anti-slave-trade policy and expanding colonial administration.
On 5 March 1867, Britain and the Netherlands signed a treaty to exchange forts and territories along the Gold Coast, aiming to create clearer zones of influence. The agreement took effect on 1 January 1868, moving several forts to new control. Instead of stabilizing the region, the swaps contributed to local resistance and exposed how fort ownership could disrupt existing political relationships.
On 6 April 1872, the Dutch Gold Coast—including Elmina—was officially ceded to the United Kingdom following Anglo-Dutch agreements signed in 1871. This ended centuries of major European competition for fort-based control on the Gold Coast. With Britain now dominant, the fort system increasingly served colonial administration and defense rather than large-scale slave exports, marking a major transition in the region’s Atlantic trade era.
European forts and castles on the Gold Coast and slave exports (1482–1872)