What they lacked were the arms so indispensable then for the work of the growing colonies, and, to say it all, the arms of the slave.
The Mussulman families, being unable to buy back their captive relatives, then offered to exchange them for a much larger number of black Africans, whom it was only too easy to carry off.

The offer was accepted by the Portuguese, who found that exchange to their advantage, and thus the slave trade was founded in Europe.
Toward the end of the sixteenth century this odious traffic was generally admitted, and it was not repugnant to the still barbarous manners.

All the States protected it so as to colonize more rapidly and more surely the isles of the New World.

In fact, the slaves of black origin could resist the climate, where the badly acclimated whites, still unfit to support the heat of intertropical climates, would have perished by thousands.

The transport of negroes to the American colonies was then carried on regularly by special vessels, and this branch of transatlantic commerce led to the creation of important stations on different points of the African coast.