French and British in west Africa: 15th - 19th century
After the Portuguese open up the African coast to trade, in the 15th century, the other European nations of the Atlantic coast are soon sending their ships into the region. The first motive is piracy. As on the Spanish Main in America, ships returning to Europe laden with booty are attractive prey.
As early as 1492 a French vessel arrives off Elmina, a fortress built ten years earlier by the Portuguese in what is now Ghana, and seizes a shipment of gold setting off for Lisbon. During the next few centuries the Portuguese face competition on these coasts from the Danes, the Dutch and the British as well as the French.
Increasingly these rival European nations sail south not to plunder Portuguese vessels but to win a share in the rich trade which the Portuguese have pioneered - in gold, ivory, gum and above all slaves. To do so they need to build their own fortified trading stations, or (a more frequent course) to seize such places already established by rivals.