Kongo monarch Nkuwu Nzinga is baptised by Portuguese missionaries, adopting the baptismal name of João I.

Nzinga-a-Nkuwu Joo I n Nzinga-a-Nkuwu, was the 5th ManiKongo of the Kingdom of Kongo (Kongo-dia-Ntotila in Kikongo language) between 1470 and 1509. He voluntarily converted to Roman Catholicism. He was baptized on 3 May 1491 and took the Christian name of Joo. Soon after, ManiKongo Nzinga-a-Nkuwu Joo I abandoned the new faith for a number of reasons, one of them being the Roman Catholic Church requirement of monogamy. Politically, the king could not afford to abandon polygamy and embrace monogamy, a cultural shift that the king could not contemplate as power in Kongo was elective, rather than hereditary as in Europe. Kongo culture followed a matrilineality structure, where the elder son of the king is not automatically the next king.

The Kingdom of Kongo (Kongo: Kongo dya Ntotila or Wene wa Kongo; Portuguese: Reino do Congo) was a kingdom located in central Africa in present-day northern Angola, the western portion of the Democratic Republic of the Congo, the Republic of the Congo as well as the southernmost part of Gabon. At its greatest extent it reached from the Atlantic Ocean in the west to the Kwango River in the east, and from the Congo River in the north to the Kwanza River in the south. The kingdom consisted of several core provinces ruled by the Manikongo, the Portuguese version of the Kongo title Mwene Kongo, meaning "lord or ruler of the Kongo kingdom", but its sphere of influence extended to neighbouring kingdoms, such as Ngoyo, Kakongo, Loango, Ndongo and Matamba, the latter two located in what is Angola today.From c. 1390 to 1862 it was an independent state. From 1862 to 1914 it functioned intermittently as a vassal state of the Kingdom of Portugal. In 1914, following the Portuguese suppression of a Kongo revolt, Portugal abolished the titular monarchy. The title of king of Kongo was restored from 1915 until 1975, as an honorific without real power. The remaining territories of the kingdom were assimilated into the colony of Angola, the Belgian Congo and the Protectorate of Cabinda respectively. The modern-day Bundu dia Kongo sect favors reviving the kingdom through secession from Angola, the Republic of the Congo, the Democratic Republic of the Congo, and Gabon.