The initial exploitation of the timber and raw materials of Madeira, the Azores, the Canary Islands, and the Cape Verde Islands had ended, and it rapidly became clear that the most profitable use of the new territories would be sugar production.

The labor involved is heavy, and Europeans refuse to work as more than supervisors.

The solution has been to bring in slaves from Africa.

The first enslaved Africans brought to Portugal had arrived in 1441 from northern Mauritania, the fruits of the expedition commanded by Lançarote de Freitas.

The maritime town of Lagos is the first slave market created in Portugal for the sale of the two hundred and thirty-five enslaved Berbers—the Mercado de Escravos, which opens in 1444.