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In page Battle of Mbwila:

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Portugal obtained an act of vassalage from D. Isabel, the regent of Mbwila, but was unable to exercise any real authority over the region once their forces had withdrawn. In 1693 they had to return to attempt to subdue the region again. The primary result in Kongo was that the absence of an immediate heir spun the country into civil war. This civil war, which raged for half a century, led to Kongo's decentralization and fundamental changes, leading to Kongolese historians, even in 1700, regarding the battle as a decisive turning point in their country's history.