Antao Gonçalves, a Portuguese explorer, began the slave trade in 1445 with the first purchase of slaves on the African coast: “nine Blacks and some gold powder in exchange for European merchandises.” Portuguese sailors continued this trade until the end of the fifteenth century. The slaves, black for the most part, were brought to Portugal or sold in the markets of Lagos, which were crowded with buyers seeking colored servants. These slaves also served in the development of the Atlantic Isles (Sao Tome, and the Cape Verde Islands) where their knowledge of agriculture and their endurance for labor were of great value. As we know, the conquistador's enslavement of indigenous people to develop the New World followed soon after its discovery, but the Indians, a fragile workforce, could not take the hard labor of the mines and fields. The obvious solution was to replace them with black slaves. Thus began the triangular trade at the start of the sixteenth century. For the next four centuries this commerce would continue to grow. It would become the largest trafficking of slaves that humanity has ever known, as well as the dominant feature in dealings between Europe and Africa south of the Sahara. The frequency and density of the human cargoes extracted from Africa would intensify until the trade's peak in the last third of the eighteenth century. Although relatively short (1800-1880), the period of underground trade that followed nonetheless inflicted a particularly significant drain on an already anemic continent.