Who usually captured the africans who were sold in the atlantic slave trade?

The Europeans captured the Africans and sold them as slaves during the Atlantic Slave Trade. The first to do this was the Portuguese however. The traders  decided to start in on the slave trade after other commodities had made them great quantities of money in the late 1400s. They then began conquering different areas of Africa in order to sell more slaves. 

Morning. sorry sjznzbz