Slavery had existed in West Africa long before the Europeans arrived there.
European slave traders seldom captured African slaves by themselves. The terrain was too difficult and the native Kingdoms often too strong for a handful of white slavers to fight. Most slaves were sold to the Europeans by other Africans.
Ashanti (modern day Ghana) traded their slaves in exchange for goods such as cloth, alcohol and guns. They then used their new resources to become more powerful and to fight wars against their neighbours in order to capture more slaves.
The Kings of Dahomey sent raiding parties into neighbouring lands with the sole purpose of capturing slaves. These slaves would then be sold to the Europeans.
It has been estimated that 326,000 slaves were taken from the Bight of Bonny between 1780 and 1800. The area around the Bight of Benin and the Bight of Bonny became known as the Slave Coast.
Some historians believe that the slave trade ruined Africa because of the constant wars and the loss of millions of strong, young people. Africa fell behind the rest of the world. Some historians think that this is why Africa was colonised by European countries in the 19th century.
Other historians draw attention to the benefits of the slave trade for African rulers - the ruling elite of native African Kingdoms prospered from the slave trade. When the British abolished the slave trade in 1807, the King of Bonny wrote to Parliament to complain.