What a person thought of European intervention, particularly their involvement in slave trade, depended on which end of the firearm they were on. Although Europe did not invent slavery, the slave trade that went on between Europe, Africa and the Americas involved an unprecedented violence enforced by weapons. There were three sides of the violence: those who owned, those who were owned, and those who were the captors. Everyone was affected. .
Nzinga Mbemba, oba, or king, of the Kongo Kingdom had all three sides of violence going on right under his nose. In the beginning, he was the equivalent of a captor in a nonphysical sense because he allowed the slave trade to go on until it was to out of hand. He welcomed the seed of European influence to be planted in his kingdom and then watched it grow out of control choking society as it did. Nzinga's initial intentions were to cooperate with and be pleasing to the Portuguese agents and officials. He went so far as to convert to Christianity, making it the state religion, and changing his African name to a Spanish one, Alfonso I. Things did not go the way he had hoped. Those under him did not approve of his new behavior. Tension grew worse as European merchants outsold African merchants and slave trade was rampant. The male population was decreasing vastly because Portuguese and hired African captors were taking all who they could get their hands on. When Alfonso realized that things were about to fall apart, he wrote several letters begging King Joao III of Portugal to have his men diminish their profligate industries. In his letters, he pleads to the king this: "And we cannot reckon how great the damage is, since the mentioned merchants are taking everyday our natives, sons of the land and the sons of our noblemen and vassals and our relatives, because the thieves and men of bad conscience grab them wishing to have the things and wares of this Kingdom which they are ambitious of; they grab them and get them to be sold; and so great, Sir, is the corruption and licentiousness that our country is being completely depopulated.