Mvemba a Nzinga or Nzinga Mbemba, also known as King Afonso I, was a ruler of the Kingdom of Kongo in the first half of the 16th century. He reigned over the Kongo Empire from 1509 to late 1542 or 1543.
Born Mvemba a Nzinga, he was the son of Manikongo (Mwene Kongo) (king) Nzinga a Nkuwu, the fifth king of the Kongo dynasty.
At the time of the first arrival of the Portuguese to the Kingdom of the Kongo's capital of M'banza-Kongo in 1491, Mvemba a Nzinga was in his thirties, and was the ruler of Nsundi province in the northeast, and the likely heir to the throne. He took the name Afonso when he was baptized after his father decided to convert to Christianity. He studied with Portuguese priests and advisers for ten years in the kingdom's capital. Letters written by priests to the king of Portugal paint Afonso as an enthusiastic and scholarly convert to Christianity. Around 1495, the Manikongo denounced Christianity, and Afonso welcomed the priests into the capital of his Nsundi province. To the displeasure of many in the realm, he had traditional art objects that might offend Portuguese sensibilities destroyed.
Afonso is best known for his vigorous attempt to convert Kongo to a Catholic country, by establishing the Roman Catholic Church in Kongo, providing for its financing from tax revenues, and creating schools.
Toward the end of his life, Afonso's children and grandchildren began maneuvering for the succession, and in 1540 plotters that included Portuguese residents in the country made an unsuccessful attempt on his life. He died toward the end of 1542 or perhaps at the very beginning of 1543, leaving his son Pedro to succeed him. Although his son was soon overthrown by his grandson Diogo (in 1545) and had to take refuge in a church, the grandchildren and later descendants of three of his daughters provided many later kings.