Portuguese forces and their Imbangala allies defeated the Kongo army at the Battle of Mbumbi.
Imbangala
The Imbangala or Mbangala were divided groups of warriors and marauders who worked as hired mercenaries in 17th-century Angola and later founded the Kasanje Kingdom.
Kingdom of Kongo
The Kingdom of Kongo was a kingdom in Central Africa. It was located in present-day northern Angola, the western portion of the Democratic Republic of the Congo, southern Gabon and the Republic of the Congo. 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", and its sphere of influence extended to neighbouring kingdoms, such as Ngoyo, Kakongo, Loango, Ndongo, and Matamba, the latter two located in what became Angola.
Battle of Mbumbi
The Battle of Mbumbi was a military engagement between forces of Portuguese Angola and the Kingdom of Kongo in 1622. Although the Portuguese were victorious, the battle served as the impetus for the Kingdom of Kongo to expel the Portuguese from their territory.