Battle of Mbidizi River

Pre-battle situation and the Kongo Civil War

In 1665 the Kingdom of Kongo clashed with their one-time allies the Portuguese at the Battle of Mbwila. The engagement resulted in a crushing Portuguese victory ending in the death of the Mwenekongo António I and most of the kingdom's nobility. Afterwards, Kongo erupted in a brutal civil war between the House of Kinlaza, which had ruled under the dead king, and the House of Kimpanzu.

Soyo, home to many Kimpanzu partisans, was eager to take advantage of the chaos. Within a few months of the national tragedy at Mbwila, the Prince of Soyo invaded the capital of São Salvador and installed his protégé, Afonso II on the throne. This happened again in 1669 with the placement of Álvaro IX on the throne. By this time both the Portuguese and the central authorities in Kongo were growing tired of Soyo's meddling. While the Kinlaza and others in Kongo lived in fear of a Soyo invasion, the governor of Luanda was afraid of the growing power of Soyo. With access to Dutch merchants willing to sell them guns and cannons plus diplomatic access to the Pope, Soyo was on its way to becoming as powerful as Kongo had been before Mbwila. Committing to the unthinkable, the weak central authority in Kongo asked Luanda to invade Soyo. In return, Portugal was promised money, mineral concessions and the right to build a fortress in Soyo to keep out the Dutch.