After a disastrous attempt at conquering the Kingdom of Ndongo, the Portuguese governor Mendes de Vasconcellos made an alliance with the Imbangala, a people described by European and Kongo sources as rootless, cannibal mercenaries originating south of the Kwanza River.

[citation needed] Captain-Major Sousa Coelho marched on Bumbi with 30,000 men, most of which were Mbundu archers supplemented by Portuguese heavy infantry and Imbangala mercenaries.

Inside the town, the Duke of Mbamba Paulo Afonso[4] and the Marquis of Pemba Cosme[5] led the Kongo forces.

Before giving battle on 18 December 1622, the Duke of Mbamba made Confession and received the Holy Sacraments before arming himself with sword, shield and relics of various saints.

A final consequence of the battle was King Pedro II's letter campaign to the Dutch proposing an alliance that would culminate twenty years later in an invasion of Angola.