Born Nzinga Mbemba, King Alfonso I was the leader of the Kongolese people in the early part of the 16th Century.  Mbemba developed a strong trade relationship with the Portuguese and adopted Catholicism as a result of this relationship. The influence of the Catholic faith reached every aspect of the King's life, from his name which was changed to Alfonso upon his acceptance of Catholicism, to his understanding of governmental organization.  Demonstrating his dedication to his religion, Alfonso named Catholicism the state religion and built many Catholic churches throughout his kingdom. In his establishing the state religion, Alfonso called for the burning of any non-Christian idols or objects related to magic and sorcery, erasing significant aspects of the Congolese cultural heritage.

The relationship between the Portuguese and the Kongo was based in trade. Alfonso adopted the Portuguese court system, and aspired to educate his elite in order to compete in international trade. The King controlled every aspect of the economic system of the Kongo, trading ivory and raffia fabric in exchange for currency he used to bring Portuguese priests, skilled tradesmen, and teachers to the Kongo to promote the education of the local elite and development of the country. The trading atmosphere was initially peaceful between the Kongo and the Portuguese nations, with letters constantly being exchanged between Alfonso and his European counterpart, Portuguese King Manuel.

This atmosphere changed when the Portuguese demanded slaves in return for their trade goods.

Although Alfonso was outspokenly opposed to slavery and initially fought the Portuguese demand for human beings, he eventually relented in order to sustain the economy of the Kongo. Initially Alfonso sent war captives and criminals to be sold as slaves to the Portuguese.  Eventually Portuguese demand for slaves exceeded the country's potential supply prompting their search for slaves from neighboring regions. Ultimately the demand for slaves destabilized the Kongo and its neighbors as all of the states in the region initiated wars to gain captives for sale to the Portuguese. Alfonso died in 1543.