Afonso I , original name Mvemba a Nzinga, also called Nzinga Mbemba, also spelled Afonso I Mvemba a Nzinga (born c. 1460—died 1542), ruler of Kongo (historical kingdom in west-central Africa) and the first of a line of Portuguese vassal kings that lasted until the early 20th century. He is sometimes called “The Apostle of Kongo” for his role in making Kongo a Christian kingdom.

Nothing is known of his early life; most of what is known of his later life originates from a remarkable series of letters he wrote between 1509 and 1541 to various kings and government officials in Lisbon and Rome. He was the son of Nzinga a Nkuwu, the first Christian king of Kongo. In 1491 he and his father were baptized by Portuguese priests and assumed Christian names, Afonso I and João I, respectively. During his father’s reign as king, Afonso served under him in various roles—including in an administrative capacity in Kongo’s northeastern province of Nsundi, which he expanded in the late 1490s. Although he was removed from the Nsundi position c. 1500, he had been restored by the time his father died some years later. Upon his father’s death, Afonso’s supporters (including his mother) wanted him to ascend as Kongo’s new king and summoned him to Mbanza Kongo, the kingdom’s capital. He managed to defeat his half brother, Mpanzu a Kitima, in battle there and succeeded as king sometime between 1506 and 1509, becoming the sixth manikongo (king of the Kongo).

During his reign, Afonso extended Kongo’s relations with Portugal, reaching an agreement (the Regimento, 1512) with Manuel I of Portugal by which the Kongo accepted Portuguese institutions, granted extraterritorial rights to Portuguese subjects, and supplied slaves to Portuguese traders. Afonso also rebuilt the kingdom’s capital using stone, expanded the kingdom to the south and east, and firmly established the Roman Catholic Church in Kongo. Working with Portuguese priests and his son (Henrique Kinu a Mvemba, who was consecrated as bishop c. 1520), Afonso shaped the doctrine of