Kongo was a rapidly Christianizing kingdom in the early 1500s. King Afonso I (born Mvemba a Nzinga) led this push to integrate with the European system: exchanging embassies with Portugal, making Portuguese the language of the court, reorganizing the nobility around European titles, even sending his son to study in Rome (where he was made a bishop).
This is an excerpt from a letter he wrote on July 6, 1526 to João III of Portugal. Note that the most notable Portuguese slaving colony at the time was tiny São Tomé.
Sire, Your Highness should know that our Kingdom is being lost in such a manner that we must provide for it with the necessary remedy. This is caused by the excessive license that your factors and officials grant to the men and merchants who come to settle in these Kingdoms and set up shop with merchandise and many things that we have forbidden — which spread through our Kingdoms and Domains in such abundance that many vassals whom we held in our obedience now break away from it, because they obtain these things in greater plenty than we ourselves: the very things with which we formerly kept them contented and subject, under our vassalage and jurisdiction. This is a great harm, both to the service of God and to the security and peace of our Kingdoms and estate.
And we do not hold this harm to be as great as that which the said merchants do in carrying off, day after day, our natives — the sons of the land, the sons of our noblemen and vassals, and our own kinsmen. For the thieves and men of evil conscience seize them, in their craving for the goods and merchandise of that Kingdom, which they covet; they seize them and carry them off to be sold. So great, Sire, is this corruption and depravity that our land is being wholly depopulated — which Your Highness ought not to countenance, nor [hold] to be your service.
And to prevent this, we have no need of anything from those Kingdoms but priests, and a few persons to teach in the schools, and no merchandise whatsoever, save only wine and flour for the Holy Sacrament. Therefore we beg Your Highness to be pleased to help and favor us in this matter, by commanding your factors to send here neither merchants nor merchandise; for it is our will that in these Kingdoms there be no trade in slaves, nor any outlet for them. For the reasons aforesaid, we beg Your Highness once again to grant us this, since otherwise we can find no remedy for so manifest a harm. May Our Lord in His clemency keep Your Highness in His protection, and ever permit you to do the things of His holy service — whose hands I kiss many times over.
(Translated by Claude from the original Portuguese; I could only find excerpts in English)
From a quick look at the rest of his Wikipedia page, it looks like he was very happily slave trading (e.g., selling slaves captured in wars of expansion) and only started complaining when the Portuguese started enslaving his subjects in a way that violated the prior Portugal-Kongo arrangements.
He was definitely not arguing from a standpoint of moral aversion to slavery or the slave trade per se. It is simultaneously true that many African nations and cultures were proudly slaving/slave-trading, that this was a moral horror that cannot be excused, and that the effects of slave trading on a mass scale destabilized the course of African statecraft.
Kongo was a rapidly Christianizing kingdom in the early 1500s. King Afonso I (born Mvemba a Nzinga) led this push to integrate with the European system: exchanging embassies with Portugal, making Portuguese the language of the court, reorganizing the nobility around European titles, even sending his son to study in Rome (where he was made a bishop).
This is an excerpt from a letter he wrote on July 6, 1526 to João III of Portugal. Note that the most notable Portuguese slaving colony at the time was tiny São Tomé.
(Translated by Claude from the original Portuguese; I could only find excerpts in English)
From a quick look at the rest of his Wikipedia page, it looks like he was very happily slave trading (e.g., selling slaves captured in wars of expansion) and only started complaining when the Portuguese started enslaving his subjects in a way that violated the prior Portugal-Kongo arrangements.
He was definitely not arguing from a standpoint of moral aversion to slavery or the slave trade per se. It is simultaneously true that many African nations and cultures were proudly slaving/slave-trading, that this was a moral horror that cannot be excused, and that the effects of slave trading on a mass scale destabilized the course of African statecraft.