Which European country first realized that there was money to be made by capturing and selling African slaves?

The major Atlantic slave trading nations, ordered by trade volume, were: the Portuguese, the British, the French, the Spanish, and the Dutch Empire. Several had established outposts on the African coast where they purchased slaves from local African leaders.[5]These slaves were managed by a factor who was established on or near the coast to expedite the shipping of slaves to the New World. Slaves were kept in a factory while awaiting shipment. Current estimates are that about 12 million Africans were shipped across the Atlantic,[6] although the number purchased by the traders is considerably higher, as the passage had a high death rate. [7][8] Near the beginning of the nineteenth century, various governments acted to ban the trade, although illegal smuggling still occurred. In the early twenty-first century, several governments issued apologies for the transatlantic slave trade.